mulog: config: Simplify config path inclusion logic

Replaced macro-based string manipulation with direct inclusion of the MULOG_INTERNAL_CONFIG_PATH. This change eliminates unnecessary complexity in the conditional compilation and enhances readability of the configuration header file.

misc: Add GitHub Release badge to README.md

This commit introduces a badge to display the current release version from GitHub in the README.md file. It enhances visibility for users to easily identify the latest software version available.