[WIP] Fix link checker errors in README.md

[Copilot]

Thanks for assigning this issue to me. I'm starting to work on it and will keep this PR's description up to date as I form a plan and make progress.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Link Checker Report</issue_title>
<issue_description># Summary

Status	Count
🔍 Total	45
✅ Successful	42
⏳ Timeouts	0
🔀 Redirected	1
👻 Excluded	0
❓ Unknown	0
🚫 Errors	2
⛔ Unsupported	0

Errors per input

Errors in README.md

• [ERROR] file:///home/runner/work/asio-coro/asio-coro/doc/ASIO-CORO%20-%20Part%20I%20-%20From%20Sync%20to%20Async%20to%20As-Sync.jpg | Cannot find file: File not found. Check if file exists and path is correct
• [ERROR] file:///home/runner/work/asio-coro/asio-coro/doc/ASIO-CORO%20-%20Part%20I%20-%20From%20Sync%20to%20Async%20to%20As-Sync.pdf | Cannot find file: File not found. Check if file exists and path is correct

Redirects per input

Redirects in README.md

• [200] https://www.boost.org/libs/asio/ | Redirect: Followed 2 redirects resolving to the final status of: OK. Redirects: https://www.boost.org/libs/asio/ --> https://www.boost.org/doc/libs/latest/libs/asio/index.html --> https://www.boost.org/doc/libs/latest/doc/html/boost_asio.html
  Full Github Actions output
  </issue_description>

<agent_instructions>I already fixed this with a recent commit, find and mention that commit here.
</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Link Checker Report #3

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