docs: added custom components

[gentaDemnushaj]

ATTENTION! NEW DOCS STRUCTURE
FOR THE NEXT THREE WEEKS, ONLY BRANCH FROM new-docs-structure
OTHERWISE, WAIT UNTIL THE NEW STRUCTURE HAS BEEN RELEASED

• Please check the internal contributions guide for details

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Thank you for contributing to the documentation.

Do the changes you have made apply to both Current and Previous versions?

Have you done a trial build to check all new or changed links?

Is there anything else you would like us to know?

This week's exciting advice from the style guide

• Write your headings in sentence case:

  • A good example
    This is a correct heading.
  • A Bad Example
    This is not a correct heading.

[matteematt]

There is an index file which is blank which you can get rid of

Apart from that really great work 🚀 Left a number of comments but they should mostly be quick fixes

[matteematt]

This page is missing an explanation of css parts. But if you think it'll take too long to do we can merge this and come back to it later

[matteematt]

I have fixed all of the trivial fixes (marking them as done on github) and merging it. We can come back to those two slightly larger points later