Phase 2: docs overlay links for clarity and accuracy

[Alberto12345678999]

Refresh various documentation files to improve overlay link references and navigation. This includes updates to converted-tier.md, cpp-conversion-enemies.md, and other related files for better user experience.

I'm just not sure about the end table of untested files at the end of cpp-conversion-enemies.

[tangos-validator]

✅ PR validation — Passed

noverify: no source/build-data changes in this PR

_{Each changed src/*.c|*.cpp is compiled and its relocated bytes compared to the binary data on a private build box. Passing requires every changed file to reproduce the ROM byte-for-byte with correct relocation targets — this catches WRONG-DEST relocations and non-reproducing near-misses that ledger-scoped linkcheck skips.}

[Alberto12345678999]

Fixed now!