Add libera.chat as default homeserver ?

**Is your feature request related to a problem? Please describe.**
With so many open source projects moving away from Freenode to Libera.chat, it would be nice to have the latter as one of the available defaults when selecting a directory.

**Describe the solution you'd like**
Add `libera.chat` entry, next to matrix.org, Freenode, OFTC, etc.

**Describe alternatives you've considered**
N/A

**Additional context**
N/A

No file or test is named. Locate the directory-selection defaults and inspect the existing entries for matrix.org, Freenode, and OFTC; add the libera.chat entry alongside them. Done means Libera.chat appears as an available default when selecting a directory.

Written by the indexing model from the issue text.