README: unify public API to str and update docs

Update README to reflect API and documentation changes: switch examples and imports from `str/core` and `str/extra` to the unified `str` module, update KMP/strategy examples to use `str` identifiers, and change the CI badge to the new GitHub Actions workflow URL. Adjust wording from “Zero Dependencies” to “Minimal Dependencies”, revise module table and structure to list `str`, `str/advanced`, `str/config` and internal implementation layout, and update usage guidance for advanced users. Also bump the release note reference from 1.2.3 to 2.0.0 and update examples that show integrating an OTP normalizer (otp_nfd) with `str` functions.

Author: lupodevelop

README.md

@@ -11,7 +11,7 @@
 <p align="center">
   <a href="https://hex.pm/packages/str"><img src="https://img.shields.io/hexpm/v/str" alt="Package Version"></a>
   <a href="https://hexdocs.pm/str/"><img src="https://img.shields.io/badge/hex-docs-ffaff3" alt="Hex Docs"></a>
-  <a href="https://github.com/lupodevelop/str/actions"><img src="https://img.shields.io/github/workflow/status/lupodevelop/str/CI?label=ci&logo=github" alt="CI"></a>
+  <a href="https://github.com/lupodevelop/str/actions"><img src="https://img.shields.io/github/actions/workflow/status/lupodevelop/str/ci.yml?branch=main&label=ci&logo=github" alt="CI"></a>
   <a href="https://opensource.org/licenses/MIT"><img src="https://img.shields.io/badge/License-MIT-yellow.svg" alt="License: MIT"></a>
 </p>
 
@@ -32,7 +32,7 @@
 | 📏 **Similarity** | Levenshtein `distance`, percentage `similarity`, `hamming_distance` |
 | 🧩 **Splitting** | `splitn`, `partition`, `rpartition`, `chunk`, `lines`, `words` |
 | 📐 **Padding** | `pad_left`, `pad_right`, `center`, `fill` |
-| 🚀 **Zero Dependencies** | Pure Gleam implementation with no OTP requirement |
+| 🚀 **Minimal Dependencies** | Pure Gleam implementation with no OTP requirement |
 
 ---
 
@@ -47,34 +47,33 @@ gleam add str
 ## 🚀 Quick Start
 
 ```gleam
-import str/core
-import str/extra
+import str
 
 pub fn main() {
   // 🎯 Grapheme-safe truncation preserves emoji
   let text = "Hello 👩‍👩‍👧‍👦 World"
-  core.truncate(text, 10, "...")
+  str.truncate(text, 10, "...")
   // → "Hello 👩‍👩‍👧‍👦..."
 
   // 🔗 ASCII transliteration and slugification
-  extra.slugify("Crème Brûlée — Recipe 2025!")
+  str.slugify("Crème Brûlée — Recipe 2025!")
   // → "creme-brulee-recipe-2025"
 
   // 🔤 Case conversions
-  extra.to_camel_case("hello world")   // → "helloWorld"
-  extra.to_snake_case("Hello World")   // → "hello_world"
-  core.capitalize("hELLO wORLD")       // → "Hello world"
+  str.to_camel_case("hello world")   // → "helloWorld"
+  str.to_snake_case("Hello World")   // → "hello_world"
+  str.capitalize("hELLO wORLD")      // → "Hello world"
 
   // 🔍 Grapheme-aware search
-  core.index_of("👨‍👩‍👧‍👦 family test", "family")
+  str.index_of("👨‍👩‍👧‍👦 family test", "family")
   // → Ok(2) - counts grapheme clusters, not bytes!
 
   // 📏 String similarity
-  core.similarity("hello", "hallo")
+  str.similarity("hello", "hallo")
   // → 0.8 (80% similar)
   
   // 🛡️ HTML escaping
-  core.escape_html("<script>alert('xss')</script>")
+  str.escape_html("<script>alert('xss')</script>")
   // → "&lt;script&gt;alert(&#39;xss&#39;)&lt;/script&gt;"
 }
 ```
@@ -134,10 +133,10 @@ pub fn main() {
 
 ```gleam
 // Force KMP explicitly
-core.index_of_strategy("long text...", "pattern", core.Kmp)
+str.index_of_strategy("long text...", "pattern", str.Kmp)
 
 // Let heuristic decide (experimental)
-core.index_of_auto("some text", "pat")
+str.index_of_auto("some text", "pat")
 ```
 
 > **Note:** `_auto` variants use heuristics and may not always choose optimally. For performance-critical code, use `_strategy` variants. Configure thresholds in `src/str/config.gleam`.
@@ -228,34 +227,34 @@ core.index_of_auto("some text", "pat")
 
 ---
 
-## 🔤 Extra Module (str/extra)
+## 🔤 Case Conversions & ASCII Folding
 
 ### Case Conversions
 
 ```gleam
-import str/extra
+import str
 
-extra.to_snake_case("Hello World")    // → "hello_world"
-extra.to_camel_case("hello world")    // → "helloWorld"
-extra.to_pascal_case("hello world")   // → "HelloWorld"
-extra.to_kebab_case("Hello World")    // → "hello-world"
-extra.to_title_case("hello world")    // → "Hello World"
+str.to_snake_case("Hello World")    // → "hello_world"
+str.to_camel_case("hello world")    // → "helloWorld"
+str.to_pascal_case("hello world")   // → "HelloWorld"
+str.to_kebab_case("Hello World")    // → "hello-world"
+str.to_title_case("hello world")    // → "Hello World"
 ```
 
 ### ASCII Folding (Deburr)
 
 ```gleam
-extra.ascii_fold("Crème Brûlée")  // → "Creme Brulee"
-extra.ascii_fold("straße")        // → "strasse"
-extra.ascii_fold("æon")           // → "aeon"
+str.ascii_fold("Crème Brûlée")  // → "Creme Brulee"
+str.ascii_fold("straße")        // → "strasse"
+str.ascii_fold("æon")           // → "aeon"
 ```
 
 ### Slug Generation
 
 ```gleam
-extra.slugify("Hello, World!")                    // → "hello-world"
-extra.slugify_opts("one two three", 2, "-", False) // → "one-two"
-extra.slugify_opts("Hello World", 0, "_", False)   // → "hello_world"
+str.slugify("Hello, World!")                    // → "hello-world"
+str.slugify_opts("one two three", 2, "-", False) // → "one-two"
+str.slugify_opts("Hello World", 0, "_", False)   // → "hello_world"
 ```
 
 ---
@@ -266,24 +265,22 @@ extra.slugify_opts("Hello World", 0, "_", False)   // → "hello_world"
 
 | Module | When to use | Import |
 |--------|-------------|--------|
-| **`str`** | Most common operations | `import str` |
-| **`str/core`** | Full grapheme-aware API, advanced features | `import str/core` |
-| **`str/extra`** | ASCII folding, slugs, case conversions | `import str/extra` |
-| **`str/tokenize`** | Reference implementation (pedagogic only) | `import str/tokenize` |
+| **`str`** | All string operations (recommended) | `import str` |
+| **`str/advanced`** | Low-level KMP algorithms, caching | `import str/advanced` |
+| **`str/config`** | Search heuristics configuration | `import str/config` |
 
-**Quick start:** Use `import str` for everyday needs. The main `str` module re-exports commonly used functions from `core` and `extra`.
+**Quick start:** Use `import str` for all your needs. The main `str` module provides the complete public API including grapheme operations, ASCII folding, slugs, and case conversions.
 
-**Advanced users:** Import `str/core` and `str/extra` directly when you need the complete API or want explicit control.
+**Advanced users:** Import `str/advanced` for explicit control over search algorithms and KMP map caching.
 
 ### Module structure
 
 ```
 str/
-├── str.gleam       # Main module (re-exports common functions)
-├── core.gleam      # Grapheme-aware utilities
-├── extra.gleam     # ASCII folding, slugs, case conversions
-├── tokenize.gleam  # Pure-Gleam tokenizer (reference)
-└── internal_*      # Character tables (not public API)
+├── str.gleam       # Main module (complete public API)
+├── advanced.gleam  # Low-level search algorithms
+├── config.gleam    # Search heuristics configuration
+└── internal/       # Implementation details (not public API)
 ```
 
 ---
@@ -305,15 +302,17 @@ str/
 The library core is OTP-free by design. For production Unicode normalization (NFC/NFD):
 
 ```gleam
+import str
+
 // In your application code:
 pub fn otp_nfd(s: String) -> String {
   // Call Erlang's :unicode module
   s
 }
 
 // Use with str:
-extra.ascii_fold_with_normalizer("Crème", otp_nfd)
-extra.slugify_with_normalizer("Café", otp_nfd)
+str.ascii_fold_with_normalizer("Crème", otp_nfd)
+str.slugify_with_normalizer("Café", otp_nfd)
 ```
 
 ---
@@ -328,7 +327,7 @@ gleam test
 python3 scripts/generate_character_tables.py
 ```
 
-Note: as of **1.2.3**, `escape_html` now uses the `houdini` library for fast, allocation‑friendly escaping, and `unescape_html` uses `odysseus` for comprehensive entity support (named, decimal and hex numeric entities). See [CHANGELOG.md](CHANGELOG.md) for details.
+Note: as of **2.0.0**, `escape_html` now uses the `houdini` library for fast, allocation‑friendly escaping, and `unescape_html` uses `odysseus` for comprehensive entity support (named, decimal and hex numeric entities). See [CHANGELOG.md](CHANGELOG.md) for details.
 
 ---