Add bilingual repository language analysis for ModSecurity v3

[Easton97-Jens]

Motivation

• Provide an explicit language analysis for the ModSecurity v3 repository to document primary and secondary languages and signal confidence in the assessment.
• Make analysis available in both German and English to aid contributors and automated tooling that need language metadata.

Description

• Add a new markdown file REPOSITORY_LANGUAGE_ANALYSIS_DE_EN.md containing a bilingual (German/English) analysis of repository languages and structure.
• The document identifies C++ as the primary language and lists secondary languages such as C, Shell, M4/Autotools, CMake, JSON, and Lua, with reasoning based on directory layout and build configuration.
• The analysis covers repository structure, filetype distribution, syntax signals, build-system context (noting C++17), weighting of core vs test files, and assigns a high confidence level.

Testing

• This is a documentation-only change and no automated tests were executed against the codebase for this change.
• No build or unit tests were required or run as part of adding the markdown analysis file.

---

Codex Task