Design Pattern Library - Add Issuable page comments

Update the brand.ai library to contain the most up-to-date design specs for issuable comments.

Example(s)

Usage

This pattern is used for all issuables (issues, merge requests, snippets) that use a comment form.

Dos and Dont's

(Use this table to add images and text describing what’s ok and not ok. This is being collected for design.gitlab)

✅ Do	🛑 Don’t

Related patterns

System notes

Links / references

Pattern checklist

Make sure these are completed before closing the issue, with a link to the relevant commit, if applicable.

1. Ensure that you have broken things down into atoms, molecules, and organisms.
2. Check that you have not created a duplicate of an existing pattern.
3. Ensure that you have used the proper method for creating the pattern depending on the complexity. Atoms and molecules are symbols, organisms are groups.
4. Make sure that text is created using text styles. When applicable used shared styles for colors.
5. QA check by another UX'r (create and reference a file in this issue which includes the changes as you would like to add them to the gitlab-elements file)