Fix link to ASTLinter class (#41)

docs/linters-development.md

@@ -4,7 +4,7 @@
 
  - [`BaseLinter`](../src/Linters/BaseLinter.php): base class of all linters, and independent from the AST
  - [`BaseASTLinter`](../src/Linters/BaseASTLinter.php): base class for linters that operate on AST nodes; you shouldn't usually extend this directly; you probably want either `ASTLinter` or `AutoFixingASTLinter` instead. You'll need to extend this if you want to use the AST to detect an issue, but an approach other than AST manipulation to automatically fix them (e.g. shelling out to `hh_client --refactor`)
- - [`ASTLinter`](../src/linters/ASTLinter.php): base class for linters that use the AST to detect issues, but don't have an auto-fix
+ - [`ASTLinter`](../src/Linters/ASTLinter.php): base class for linters that use the AST to detect issues, but don't have an auto-fix
  - [`AutoFixingLinter`](../src/Linters/AutoFixingLinter.php): an interface that specifies that a linter is able to fix   its' own lint problems
  - [`AutoFixingASTLinter`](../src/Linters/AutoFixingASTLinter.php): a subclass of `ASTLinter` which implements `AutoFixingLinter`, for when your auto-fix is based on an AST mutation
  - [`FunctionNamingLinterTrait`](../src/Linters/FunctionNamingLinterTrait): helper for `ASTLinter` subclasses