Create upgrade guide for Plone 6.2 backend.

[mauritsvanrees]

For technical review, I tag @davisagli @gforcada @petschki.

I have fixed most Vale feedback, except these, which I don't know how to write better:

venv/bin/vale --no-wrap  docs/backend/upgrading/version-specific-migration/upgrade-to-62.md

 docs/backend/upgrading/version-specific-migration/upgrade-to-62.md
 33:11  suggestion  'is deprecated' looks like passive voice.    Microsoft.Passive         
 33:44  suggestion  'be removed' looks like passive voice.       Microsoft.Passive         
 62:29  warning     Avoid using acronyms in a title or heading.  Microsoft.HeadingAcronyms 

That last one is for "Classic UI" in the last header, I think.

---

📚 Documentation preview 📚: https://plone6--2002.org.readthedocs.build/

Specifically this page: /backend/upgrading/version-specific-migration/upgrade-to-62.

[stevepiercy]

You can ignore Vale warnings and suggestions, but errors should get a look. As part of my routine maintenance, I try to address the errors and reduce them. There's a long way to go yet, so the only thing I really care about for now is to not introduce new errors. Often it turns out to be a candidate for a new term in the glossary, and sometimes it's just some bad MyST markup.

I'll do a thorough editorial review in the next day or so, after the smart people do a technical review. Thanks for the PR!

[gforcada]

Nice write up!

[petschki]

thanks @mauritsvanrees ... currently there is nothing more to say for the template movements. Progress is tracked here plone/Products.CMFPlone#3953

[stevepiercy]

Minor tweaks, and a question and suggestion for reference to Python docs. I'm not sure if I got it right. Thanks for your work on this. It's really good!

[stevepiercy]

We should include references to the following terms.

• Native namespace packages
• PEP 420 – Implicit Namespace Packages

If I read all that correctly, a native namespace is a subcategory of implicit namespaces. Is that right?

If so, then I'd make the following suggestion.

Suggested change

	There are three styles or techniques of namespaces.
	For Plone only two are important: `pkg_resources` and native (sometimes referred to as implicit).
	The third style is `pkgutil`, but Plone has never used it.
	There are three styles or techniques of namespaces.
	For Plone, only two are important: `pkg_resources` and native, the latter of which is a subcategory of implicit namespace packages where you omit the `__init.py__` file from the namespace package directory.
	The third style is `pkgutil`, but Plone has never used it.
	```{seealso}
	- [Native namespace packages](https://packaging.python.org/en/latest/guides/packaging-namespace-packages/#native-namespace-packages)
	- [PEP 420 – Implicit Namespace Packages](https://peps.python.org/pep-0420/)
	```

[stevepiercy]

@mauritsvanrees I committed all but this one suggestion, as I'd like your thoughts on it.

[davisagli]

This suggestion seems helpful to me.

[mauritsvanrees]

Adding the links is good.

But I don't see where you got the impression that native namespace are a subset of implicit namespaces. As far as I know, there is no difference, they are two terms for the exact same thing.

Your first link says: "Python 3.3 added implicit namespace packages from PEP 420. All that is required to create a native namespace package is that you just omit __init__.py from the namespace package directory." The text points to your second link, the official PEP, and the term "native" is not even mentioned there.

I asked Duck.AI, but that answer was just clearly wrong, restricting native to namespaces that exist within one package and still have an __init__.py, though empty.

@davisagli Do you know a difference between the two?

[stevepiercy]

Your first link says: "Python 3.3 added implicit namespace packages from PEP 420. All that is required to create a native namespace package is that you just omit __init__.py from the namespace package directory." The text points to your second link, the official PEP, and the term "native" is not even mentioned there.

Yes, that's exactly why I was uncertain. I can ask in Python's doc Discord channel to see what they say, too.

[davisagli]

Aside from the pending suggestion, this looks good to me.

[mauritsvanrees]

I have rebased on 6.0 and force pushed, because the merge and revert of the multilingual PR which added the same file, gave a conflict.

[petschki]

I've created a TinyMCE license key config documentation here #2012

we should mention here, that TinyMCE got updated to v8 and that you're able to provide commercial tinymce license keys now.