- Add vcs-browser URL
- Fix donation URL

"The old generator also included all the none-value entries—it
no longer does this, you can safely remove them.

If it only consists of none values, it’s safe to shorten it to just:
`<content_rating type="oars-1.1" />`"

More information: https://docs.flathub.org/docs/for-app-authors/appdata-guidelines/#oars-information

Mibbit says "irc.gnome.org: Terminated"; also add Matrix.

Mibbit says "irc.gnome.org: Terminated"; also add Matrix.

Mibbit says "irc.gnome.org: Terminated"; also add Matrix.

Closes #28

Alexander Shopov authored Oct 08, 2022 and Administrator committed Oct 08, 2022

(cherry picked from commit 3dcb0f59)