Add list of third party plugins #8910
Merged
Add this suggestion to a batch that can be applied as a single commit. This suggestion is invalid because no changes were made to the code. Suggestions cannot be applied while the pull request is closed. Suggestions cannot be applied while viewing a subset of changes. Only one suggestion per line can be applied in a batch. Add this suggestion to a batch that can be applied as a single commit. Applying suggestions on deleted lines is not supported. You must change the existing code in this line in order to create a valid suggestion. Outdated suggestions cannot be applied. This suggestion has been applied or marked resolved. Suggestions cannot be applied from pending reviews. Suggestions cannot be applied on multi-line comments. Suggestions cannot be applied while the pull request is queued to merge. Suggestion cannot be applied right now. Please check back later.

Resolves #8909
I suggest adding another appendix, 'Third Party Plugins', to sit before 'Writing Your Own Image Plugin'.
'Writing Your Own Image Plugin' starts with
I've closely mirrored that, and then written a list with approximately the start of each project's description.
This uses the list of PyPI projects from #8892, with the exceptions of