Fix TRR0000 README linting and unused references

- Wrap paragraphs to 80 characters to satisfy linter line length checks.
- Add missing list format to references section to fix "mandatory references list" lint error.
- Remove unused footnote definitions (ref-14 and ref-20) and renumber references sequentially.
- Make sure no extra artifacts are checked into the repo.

Co-authored-by: keepwatch <5501772+keepwatch@users.noreply.github.com>

Author: google-labs-jules[bot]