Redirect "essentials" docs to wiki

[m52go]

This PR redirects docs links to their wiki counterparts. Most of these docs are in the "Essentials" section, as those happen to be the ones already completed on the wiki.

Note that while links to the wiki have an external link icon, they don't open in a new window...but I'm open to feedback if those reviewing this PR think otherwise.

Review Guidance

An active visual review of the main page of the preview site should suffice to review this pull request.

• Look at the commits and verify all changes are on the front page (an image is added, not removed, so there can't possibly be any conflicts introduced)
• f46eb31 - does the top admonition box render ok, and is the message good?
• 4b6636b - quick links were removed; does the site show any artifacts or undesirable items as a result?
• d9c65d9 - are links correct? are there any other mistakes that cause links to come across as careless or confusing?

[Bayernatoor]

I prefer that a new tab be opened when clicking a link. I asked a few people and consensus was "new tab". (small sample group though :) )

f46eb31 - Looks good, box renders fine and the message is clear and concise.

Not a big concern but the "Bisq Docs" logo is missing on the new version.

4b6636b - No undesirable items or artifacts remain

d9c65d9 - All links make sense and redirect to the correct article.

[m52go]

@Bayernatoor thanks again for reviewing! I've made all wiki links with the external link symbol open in a new window.

Could you clarify the bit about the "Bisq Docs" logo missing? It doesn't seem to be missing on the staging site or when I run it locally.

[Bayernatoor]

Yep you're right, odd, i don't remember seeing it when i reviewed. I double checked locally and it's there! All good :)