refactor: move entrypoints from x/init.lua to x.lua

This makes config and languages module loading slightly simpler.
Now all the actual config files can be in the same directory and
initialisation can be separated.

Author: peter-bread

README.md

@@ -124,7 +124,7 @@ after/
 Programming languages are managed in
 [`lua/peter/languages/<language>.lua`](./lua/peter/languages/). Each of these
 files should return a table of type `peter.lang.config`. The type is defined in
-[`lua/peter/languages/init.lua`](./lua/peter/languages/init.lua) and shown
+[`lua/peter/languages.lua`](./lua/peter/languages.lua) and shown
 below:
 
 ```lua
@@ -158,9 +158,9 @@ Instead of calling these directly in in the `plugins` field, you can include
 table fields with the same name (see example below).
 
 Language configs are processed in
-[`lua/peter/languages/init.lua`](./lua/peter/languages/init.lua). This builds
-and exposes a table which maps language names to configurations. This table can
-be accessed with:
+[`lua/peter/languages.lua`](./lua/peter/languages.lua). This builds and exposes
+a table which maps language names to configurations. This table can be accessed
+with:
 
 ```lua
 -- Whole table.

lua/peter/config/init.lua lua/peter/config.lualua/peter/config/init.lua renamed to lua/peter/config.lua

@@ -1,6 +1,3 @@
--- THIS FILE DOES NOT CONTAIN THE CONFIGURATION FOR A SPECIFIC PROGRAMMING
--- LANGUAGE.
---
 -- THIS FILE LOADS ALL OF THE OTHER LANGUAGE CONFIG FILES INTO A SINGLE LUA
 -- MODULE THAT CAN BE ACCESSED USING `require("peter.languages")`.
 
@@ -10,7 +7,7 @@ local function is_valid_module(file)
   -- We could use `vim.filetype.match({ filename = file })` but this would allow
   -- files like `go.lua.bak`, which should not be included in the actual config
   -- as they are backups.
-  return file:sub(-4) == ".lua" and file ~= "init.lua"
+  return file:sub(-4) == ".lua"
 end
 
 ---@class (exact) peter.lang.Config