Merge pull request #24 from WordPress/naming-conventions

Adds naming conventions to contributing doc

Author: JasonTheAdams

CONTRIBUTING.md

@@ -8,6 +8,16 @@ While this project is stewarded by [WordPress AI Team](https://make.wordpress.or
 
 All parameters, return values, and properties must use explicit type hints, except in cases where providing the correct type hint would be impossible given limitations of the oldest supported PHP version (see below).
 
+## Naming conventions
+
+The following naming conventions must be followed for consistency and autoloading:
+
+- Interfaces are suffixed with `Interface`.
+- Traits are suffixed with `Trait`.
+- Enums are suffixed with `Enum`.
+- File names are the same as the class, trait, and interface name for PSR-4 autoloading.
+- Classes, interfaces, and traits, and namespaces are not prefixed with `Ai`, exluding the root namespace.
+
 ## PHP Compatibility
 
 All code must be backward compatible with PHP 7.4, which is the minimum required PHP version for this project.