Add changelog for ppxlib 0.30.0

[tmattio]

@pitag-ha what would you like to see highlighted in the announcement apart from the compat with 5.1?

[pitag-ha]

Do you think the following would be too long? Btw, I haven't put much thought into the wording, feel free to rephrase it.

[pitag-ha]

Suggested change

	This release comes with support for OCaml 5.1 and brings several improvements and bug fixes.
	This release comes with support for OCaml 5.1 and brings several improvements and bug fixes.
	On the side of writing PPXs, the user experience of `Ast_pattern` and `metaquot` have been
	improved by adding more utility functions to the former and improving the error reporting of
	the latter. On the side of using PPXs, the experience of compatibility with OCaml `trunk`
	has been improved: the Driver gets biased into recognizing the accurate Parsetree version on
	non-unique Parsetree magic numbers, allowing for general compatibility with both `trunk` and
	stable OCaml versions at the same time. Furthermore, the release makes Ppxlib compatible
	with ReScript by adding "ns" and "res" as reserved namespaces.

[tmattio]

That's perfect, I'll use this and rephrase it if needed, thanks!

[tmattio]

Ready to go when Ppxlib lands on opam-repository (ocaml/opam-repository#23965).

@christinerose don't hesitate to have a look as well if you want

[christinerose]

I asked a few questions about formatting certain words for the purpose of clarity.

[pitag-ha]

Thanks @christinerose! With your review, I've noticed how sloppy we are with formatting/readability of changelog entries. I'll try to pay more attention to it.

[christinerose]

Thanks @christinerose! With your review, I've noticed how sloppy we are with formatting/readability of changelog entries. I'll try to pay more attention to it.

No worries! It's my job to ensure things are consistent and clear, so I'm more than happy to do it!! In fact, being the English geek I am, I really enjoy it. 😊