From af360107cd669bfcc89fec7577927dc7ae7f55e3 Mon Sep 17 00:00:00 2001
From: Yury Bayda <yury@bayda.pro>
Date: Sun, 2 Aug 2026 20:40:44 -0700
Subject: [PATCH] ci: lint Markdown

---
 .github/workflows/main.yml |  5 +++++
 .markdownlint.json         |  8 ++++++++
 README.md                  | 18 +++++++++---------
 3 files changed, 22 insertions(+), 9 deletions(-)
 create mode 100644 .markdownlint.json

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index dd59feb..b1e9be8 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -13,6 +13,11 @@ jobs:
     steps:
       - uses: actions/checkout@v7
 
+      - name: Lint Markdown
+        uses: DavidAnson/markdownlint-cli2-action@v23
+        with:
+          globs: "**/*.md"
+
       - uses: actions/setup-python@v7
         with:
           python-version: "3.11"
diff --git a/.markdownlint.json b/.markdownlint.json
new file mode 100644
index 0000000..2bf8ad4
--- /dev/null
+++ b/.markdownlint.json
@@ -0,0 +1,8 @@
+{
+  "MD013": {
+    "line_length": 100
+  },
+  "MD024": {
+    "siblings_only": true
+  }
+}
diff --git a/README.md b/README.md
index eece9ea..051b572 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,7 @@ test-driven development.
 
 ## Instructions
 
-Roman numerals are a numeral system that was used by ancient Rome. Numbers in 
+Roman numerals are a numeral system that was used by ancient Rome. Numbers in
 this system use letters from the Latin alphabet. Currently, it uses seven symbols:
 
 | Symbol | Value |
@@ -38,9 +38,9 @@ In general, the values for 5, 50, and 500 are not subtracted.
 The task at hand entails crafting a function `to_roman(number: int) -> str` to
 convert regular Arabic numbers into Roman numerals, such as:
 
-* 4 → IV
-* 7 → VII
-* 9 → IX
+- 4 → IV
+- 7 → VII
+- 9 → IX
 
 The lowest number you can write in Roman Numerals is number I (1). And the
 largest numeral is MMMCMXCIX (3999).
@@ -51,15 +51,15 @@ In this phase, the objective is to develop a function `from_roman(number: str)
 -> int` that performs the reverse conversion, transforming Roman numerals into
 their corresponding Arabic digits.
 
-## Guiding Principles
+## Guiding principles
 
-* If you don't know an existing algorithm, follow the principles of strict
+- If you don't know an existing algorithm, follow the principles of strict
   Test-Driven Development (TDD) to derive one.
-* Reflect on whether the sequence in which you write tests influences the final
+- Reflect on whether the sequence in which you write tests influences the final
   design of your algorithm.
-* Consider whether it's more beneficial to devise an algorithm before embarking
+- Consider whether it's more beneficial to devise an algorithm before embarking
   on TDD, especially if you don't already know one.
-* If you do know an algorithm, evaluate if it can be implemented using strict
+- If you do know an algorithm, evaluate if it can be implemented using strict
   TDD principles.
 
 ## Prerequisites