contrib : filename guidelines [no ci]

CONTRIBUTING.md

@@ -84,7 +84,7 @@
 
     - The `get` `<action>` can be omitted
     - The `<noun>` can be omitted if not necessary
-    - The `_context` suffix of the `<class>` is optional
+    - The `_context` suffix of the `<class>` is optional. Use it to disambiguate symbols when needed.
     - Use `init`/`free` for constructor/destructor `<action>`
 
 - Use the `_t` suffix when a type is supposed to be opaque to the user - it's not relevant to them if it is a struct or anything else
@@ -98,6 +98,9 @@
     > [!NOTE]
     > This guideline is yet to be applied to the `llama.cpp` codebase. New code should follow this guideline.
 
+- C/C++ filenames are all lowercase with dashes. Headers use the `.h` extension. Source files use the `.c` or `.cpp` extension
+- Python filenames are all lowercase with underscores
+
 - (TODO: abbreviations usage)
 
 # Preprocessor directives