Check docs are up to date

[ErikSchierboom]

Please check if your documentation files are still up-to-date.

The key documentation files to check are:

• docs/ABOUT.md
• docs/INSTALLATION.md
• docs/LEARNING.md
• docs/RESOURCES.md
• docs/TESTS.md
• exercises/shared/.docs/help.md
• exercises/shared/.docs/tests.md

There might be more.

Link check report

To help identify invalid links, we've automatically checked the links of all *.md files in this repo.
This is the report of that check:

📝 Summary
---------------------
🔍 Total...........71
✅ Successful......70
⏳ Timeouts.........0
🔀 Redirected.......0
👻 Excluded.........0
🚫 Errors...........1

Errors in ./docs/LEARNING.md
✗ irc://irc.freenode.net/d (builder error for url (irc://irc.freenode.net/d): URL scheme is not allowed)

Tracking

exercism/v3-launch#54

[BNAndras]

https://archlinux.org/packages/community/x86_64/dub/ returns a 404 on the installation page as well.

I'll take a look at the content overall.