Some attributes in documentation does not have information letting users know about slots

[yucheng11122017]

Please confirm that you have searched existing issues in the repo

Yes, I have searched the existing issues

Any related issues?

No response

Tell us about your environment

Windows 10

MarkBind version

5.4.0

Describe the bug and the steps to reproduce it

According to MdAttributeRenderer.ts, there are attributes which users can override using a slots.
But it does not seem to be reflected on the user guide.

For example, a-point seems to support header, label, content slots but this is not documented

Expected behavior

Solution:

• Check that these attributes actually support slots
• Add documentation regarding slots for these attributes

Anything else?

No response

[yucheng11122017]

Bringing over the summary from #2511 here - feel free to edit this message to bring it up to date. I might have missed something - let me know!

Referring to packages/core/test/unit/html/NodeProcessor.test.ts

Component	Attributes	Documented?	Tested?
Panel	Header, Alt	Yes(?)	(Alt seems to not be tested?)
Box	Icon, Header	?	Not tested
Popover	Header, Content	Yes	Yes
Modal	Header	?	Not tested
Dropdown	Header	?	Yes
Scroll-top-button	Icon	?	Not tested
Question	Header, Hint, Answer	Yes	Yes
Q-Option	Reason	Yes	Yes
Quiz	Intro	Yes	Yes
Tooltip	Content	?	Not tested
Tab	Header	?	Not tested
A-Point	Header, Content, Label	No	Not tested
So when adding tests for these 6 not tested parts we should also update docs

Quoting from old issue in this PR!