docs: update Doxygen configuration and main page #56

Job	Run time
ASan + UBSan (Ubuntu)	3m 41s
UBSan (Ubuntu)	2m 4s
Build & Test (ubuntu-24.04)	3m 1s
TSan (Ubuntu)	2m 25s
Build & Test (Windows / MSVC)	4m 33s
Build & Test (macos-14)	1m 36s
Post-Quantum PQ (Ubuntu)	3m 57s
Python SAST (bandit)	13s
Benchmarks (Ubuntu)	2m 33s
Fuzz (Ubuntu, Clang-18)	30m 50s
Server Codecs (Ubuntu)	4m 27s
Mutation Testing Baseline (Ubuntu)	28s
Coverage (Ubuntu, Clang-18)	2m 16s
License Compliance	1m 41s
Full Suite 394/394 (Ubuntu)	4m 10s
Secrets Scan (gitleaks)	6s
	1h 8m 1s

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