move pages to /links folder, add navigation groups

[MuxaJIbI4]

Also:

• Historical-SoC-Outreachy.md split into 2 separate files for Soc and Outreachy.
• support ordering items inside navigation group using 'order:' property tested on 'Rev News' group

see issue #830 for full description.

[chriscool]

I think we should start with 3 top level categories only:

- Git Development
  - Hacking-Git
- Git Rev News
  - <pages related to Git Rev News>
  - ...
- Mentoring Programs
  - <pages common to GSoC and Outreachy>
  - ...
  - <pages specific to GSoC>
  - ...
  - <pages specific to Outreachy>
  - ...

We can also split Historical-SoC-Outreachy.md later.

Thanks.

[MuxaJIbI4]

@chriscool

We can also split Historical-SoC-Outreachy.md later.

Returned original file.

I think we should start with 3 top level categories only:

Updated 3 groups to "Mentoring*", still separated to 3 groups so that files don't mix.

On https://muxajibi4.github.io/git.github.io/ works but without CSS (relative url problem)
This is preview from my local version (red lines - some interesting titles to possibly change):

[chriscool]

I have pushed the changes that were suggested by your red lines. For SoC-2022-Org-Application.md, I just removed it from the navbar as it's outdated.

You suggest "Mentoring-GSoC", but the fact that "GSoC" in "GSoC participants" was in red made me rename it to "SoC participants" as the title of other GSoC related material starts with "SoC". So you should suggest "Mentoring-SoC" to be consistent.

[chriscool]

Also please squash your commits together unless you find a good way to separate the work into separate atomic commits.

[MuxaJIbI4]

@chriscool created 1 squashed commit from HEAD of master.