Added an entry for linux-meta and linux-signed

[Jetoson]

This PR adds an entry for linux-meta and linux-signed in the glossary.

Fixes #7

[AnneCYH]

Hi @Jetoson , thanks so much for your continued contributions!

I left some comments, and I have some general advice on the PRs.

If you are using a line length limit, it would be good to stick to it. For example, linux-meta and linux-signed entries seem to cut off at a specific character count but the SRU entry doesn't wrap the lines, per se. :) It would be easier for readability if the code (in this case 'docs code') is consistently formatted within the file (and hopefully within the repo!).

Another thing, which was not enabled properly. You can preview the PR builds if you click on "Details" for the "docs/readthedocs.com:canonical-kernel-docs" check. This is particularly useful for changes with a larger scope or content with a lot of nesting / formatting etc. :)

As always, let us know if you have any questions, thanks!

[AnneCYH]

Hi @Jetoson , as a gentle reminder of other opportunities available for contributing to docs; which might spark your interest in contributing to the many other open source projects in Canonical.

Canonical has the Open Documentation Academy, which is a platform for you to connect with the Documentation team at Canonical, and also a place to start getting involved in open source through documentation.
Read more about the ODA here:
https://canonical.com/documentation/open-documentation-academy

There are also specially curated issues which anyone who is interested can contribute to here, as part of the ODA efforts:
https://github.com/canonical/open-documentation-academy/issues

Thank you!

[Jetoson]

Thank you @AnneCYH for your gentle feedback, I'm learning a lot about opensource contribution and kernel development. And thank you for the heads up about ODA, it is a great platform. I'm really excited!

[AnneCYH]

Thanks @Jetoson , looks good! Thanks so much for your time & effort.
I'm going to go ahead and merge it.