Complete documentation coverage: add final module docstrings

Co-authored-by: varun-r-mallya <100590632+varun-r-mallya@users.noreply.github.com>

Author: Copilot

pythonbpf/debuginfo/dwarf_constants.py

@@ -1,3 +1,9 @@
+"""
+DWARF debugging format constants.
+
+Generated constants from dwarf.h for use in debug information generation.
+"""
+
 # generated constants from dwarf.h
 
 DW_UT_compile = 0x01

pythonbpf/functions/return_utils.py

@@ -1,3 +1,10 @@
+"""
+Utility functions for handling return statements in BPF functions.
+
+Provides handlers for different types of returns including XDP actions,
+None returns, and standard returns.
+"""
+
 import logging
 import ast