Add known limitations section

[e-grapp]

Description

Added a section to include known issues and limitations

Reasons

https://circleci.atlassian.net/browse/SC-736

Content Checklist

Please follow our style when contributing to CircleCI docs. Our style guide is here: https://circleci.com/docs/style/style-guide-overview.

Please take a moment to check through the following items when submitting your PR (this is just a guide so will not be relevant for all PRs) 😸:

• [ ] Break up walls of text by adding paragraph breaks.
• [ ] Consider if the content could benefit from more structure, such as lists or tables, to make it easier to consume.
• [ ] Keep the title between 20 and 70 characters.
• [ ] Consider whether the content would benefit from more subsections (h2-h6 headings) to make it easier to consume.
• [ ] Check all headings h1-h6 are in sentence case (only first letter is capitalized).
• [ ] Is there a "Next steps" section at the end of the page giving the reader a clear path to what to read next?
• [ ] Include relevant backlinks to other CircleCI docs/pages.

[sebastian-lerner]

@rosieyohannan any chance you can help merge this?

[imlogang]

I fixed the status-badge.adoc lint error but seems the build job failed, so will need @rosieyohannan to rerun.

[imlogang]

SSO was being weird. Was able to rerun the build job.