change asdf standard changelog entries to notes

[braingram]

Description

Since towncrier renders sub-sections with - and we include out CHANGES.rst in the docs we run into issues due to previous sub-sections with ^ marking the then-current ASDF-standard version.

This PR changes the ^ sub-sections to .. note:: to avoid the conflict with towncrier.

Checklist:

• pre-commit checks ran successfully
• tests ran successfully
• for a public change, added news fragment (changes/<PR#>.<changetype>.rst)
• for a public change, updated documentation
• for any new features, unit tests were added

[braingram]

@zacharyburnett I think something is not quite right with the towncrier configuration. When I run towncrier build --draft I see:

Loading template...
Finding news fragments...
Rendering news fragments...
Draft only -- nothing has been written.
What is seen below is what would be written.

3.4.1.dev6+gfe07e2df.d20240807 (2024-08-19)
===========================================

Misc
----

- `#1828 <https://github.com/asdf-format/asdf/pull/1828>`_, `#1830
  <https://github.com/asdf-format/asdf/pull/1830>`_

It appears towncrier is throwing away the fragment contents. This can be seen in the docs too: https://asdf--1830.org.readthedocs.build/en/1830/asdf/changes.html#dev41-ge304a781-2024-08-19

[braingram]

I mistakenly thought misc fragments would be shown. This isn't the case (they default to showcontent=False). I'll update this PR to use doc instead.

I'd also like to see if we can make misc show content (without having to redefine all the default sections). It seems a little silly to write a fragment that will later be thrown out.

[zacharyburnett]

I mistakenly thought misc fragments would be shown. This isn't the case (they default to showcontent=False). I'll update this PR to use doc instead.

I'd also like to see if we can make misc show content (without having to redefine all the default sections). It seems a little silly to write a fragment that will later be thrown out.

that's a good point; we will unfortunately have to redefine all the non-default fragment types, but that shouldn't be too difficult