docs(rpp): refresh docs for monorepo move, TheRock delivery, and 3.2.0

[kiritigowda]

JIRA ID : ROCM-20223

Summary

Refreshes RPP documentation to match its current status as a monorepo project delivered via TheRock.

• Document monorepo move (ROCm/rpp → ROCm/rocm-libraries) and TheRock delivery for ROCm 7.15+; drop OpenCL references (removed in 3.0.0)
• Rebuild the CPU/GPU support matrix from the current API headers; replace the un-diffable PNG with Markdown tables in the README and sync the docs .rst table (101 entries, verified in sync)
• Bump version to 3.2.0 and consolidate the CHANGELOG unreleased section; wire Doxygen version from CMakeLists
• Fix stale links, typos, and remove the outdated RPP-functions.csv

Test plan

• Docs build (Sphinx + Doxygen) renders without warnings
• README Markdown tables and collapsible sections render correctly on GitHub

[therock-pr-bot]

✅ All Checks Passed — Ready for Review

Check	Status	Details
📝 PR Description	✅ Pass	—
⛔ Forbidden Files	✅ Pass	—
🧪 Unit Test	⚠️ Warning	Error: Source/code files changed without an accompanying unit test. Expected: add at least one test file named like test_<name>.py / test_<name>.cpp (or <name>_test.*). Current: code file(s) changed: projects/rpp/docs/conf.py; no test file found
🔎 pre-commit	✅ Pass	—
🚫 Draft PR	🔜 To Be Enabled	—
🚩 Feature Flag	🔜 To Be Enabled	—
📊 Code Coverage	🔜 To Be Enabled	—
🤖 therock-pr-bot	✅ Pass	—

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[therock-pr-bot]

🎉 All checks passed! This PR is ready for review.