fix: correct readme templated-by parsing for multiple indicators

[JoshuaKGoldberg]

PR Checklist

• Addresses an existing open issue: fixes 🐛 Bug: Transition mode duplicates some "templated by" notices #2141
• That issue was marked as status: accepting prs
• Steps in CONTRIBUTING.md were taken

Overview

The two parts of README.md parsing for documentation that care about these notices are:

• additional: which cares about the first notice
• footnotes: which cares about the last notice

I considered merging the two read* functions into a single one, but figured I could save that refactor for if this gets even more complicated / intertwined.

🎁

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.81%. Comparing base (c0fa41b) to head (07e23cb).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2142   +/-   ##
=======================================
  Coverage   99.81%   99.81%           
=======================================
  Files         129      129           
  Lines        5461     5475   +14     
  Branches      395      399    +4     
=======================================
+ Hits         5451     5465   +14     
  Misses         10       10           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[github-actions]

🎉 This is included in version v2.26.6 🎉

The release is available on:

• GitHub releases
• npm package (@latest dist-tag)

Cheers! 📦🚀