keda-docs Adding HTTP scaling documentation

This PR moves documentation about the HTTP Addon from the HTTP Addon repo. This PR is incomplete at the moment, but below is my idea for organization:

HTTP appears in the "Docs" dropdown on the nav bar, and directs to /docs/http
/docs/http contains a simple intro page as well as all of the documents currently in https://github.com/kedacore/http-add-on/tree/main/docs
/docs/2.4/concepts/ has "Scaling HTTP Applications" on the sidebar. That goes to an overview page, which contains links to /docs/http

Checklist

[x] Commits are signed with Developer Certificate of Origin (DCO)
[x] Add scaler intro doc to "concepts" dropdown
[ ] Move documentation from HTTP Addon wiki to subsection (e.g. /docs/http)
[ ] Version the documentation?

After this PR is merged, most documentation from the docs/ directory should be on the site, and removed from the http addon repo. Similarly, the wiki on the HTTP Addon repository should be removed in favor of this site.

Fixes #548

Oct 14 '21 17:10 arschles

@tomkerkhove can you let me know what you think about this initial layout?

Oct 14 '21 17:10 arschles

I am not seeing the HTTP page, is it possible that you forgot to add it?

Oct 15 '21 06:10 tomkerkhove

@tomkerkhove indeed it is. sorry about that - I'll check this out tomorrow and get it fixed up.

Oct 21 '21 22:10 arschles

No rush!

Oct 22 '21 05:10 tomkerkhove

@tomkerkhove I added a content/docs/2.4/http section so a page shows up under the /docs/2.4/http/ path, but I'm kind of confused what types of docs should go under there vs. the concept page at /docs/2.4/concepts/scaling-http/. Is there a best practice for that?

Oct 22 '21 15:10 arschles

@tomkerkhove there are 2 more TODOs on this PR, but I'm moving this out of draft now. I think it would be good to get a basic layout merged, and then I can add more content in follow-ups. If you agree, I'll pull the remaining TODOs out into issues. WDYT?

Nov 10 '21 19:11 arschles