docs: index: matrix.org IRC bridge, contributing
Mention the matrix.org IRC bridge as primary means to access
`#isso`.
"Contribute" section mentions more ways than just writing
code, so adjust link text on index accordingly.
</ul>
<h2>Help</h2>
<p>
- Join <code>#isso</code> on <a href="https://libera.chat/">Libera.Chat</a>
+ Join <code>#isso</code> via <a href="https://matrix.to/#/#isso:libera.chat">Matrix</a>
+ or via IRC on <a href="https://libera.chat/">Libera.Chat</a>,
or ask a question on <a href="https://github.com/posativ/isso/discussions">GitHub Discussions</a>.
</p>
<h2>Contribute</h2>
<p>
- <a href="{{ pathto('contribute') }}">Write Code</a> or
+ <a href="{{ pathto('contribute') }}">Ways to Contribute</a> or
<a href="https://www.transifex.com/projects/p/isso/">Translate</a>
</p>
