Add Lemmy to socials and small community area updates

[Daeraxa]

This PR does a few things:

• Adds a Lemmy blog post announcing it to the wider public
• Adds an extra CSS class to centre blog images without breaking anything else
• Updates our community areas
• Updates the "get help" to link to the community areas so we don't maintain two lists.
• Changes the repo issue links to recommend people search first and then a direct link to the bug report. This was originally put in very early before all of the templates were added.

You will notice the emojis in the footer and community area list uses fa-users which is just a generic group of people - Lemmy has yet to be added to Font Awesome (FortAwesome/Font-Awesome#19758).

Either way it isn't an issue yet as the site is still a bit broken when it comes to FA icons pending a move to the new framework and the rather complicated PR needed to update the Vuepress theme.

[confused-Techie]

Looks great!

Especially love the deduplication of information we have to maintain. That's always a huge bonus