PHP 8.1 | Migration guide: add IMAGETYPE_AVIF constant

[rodrigoprimo]

Add the IMAGETYPE_AVIF constant to the PHP 8.1 migration guide.

The Standard section was placed at the end of the file, after Tokenizer, following the pattern used in the PHP 8.5 migration guide. I'm not sure if this is correct or not.

Refs:

• AVIF support for getimagesize() and imagecreatefromstring() php-src#7091

[lacatoire]

LGTM! Thanks @rodrigoprimo IMAGETYPE_AVIF confirmed in src

[cweiske]

Please sort the ids/sections alphabetically (put yours into the correct sort position).

[rodrigoprimo]

Thanks for the review and for confirming the correct sort order, @cweiske!

I applied your suggestion. The Standard section is now in its correct alphabetical position, between Sodium and Tokenizer.

As mentioned in the PR description, I had originally placed it at the end following the pattern used in the PHP 8.5 migration guide. Should that one be fixed as well in a separate PR?

[cweiske]

As mentioned in the PR description, I had originally placed it at the end following the pattern used in the PHP 8.5 migration guide. Should that one be fixed as well in a separate PR?

Feel free to do that.

[rodrigoprimo]

Feel free to do that.

@cweiske, I just realized that #5437 was not merged yet, and there will be conflicts if I open another PR to update the order of the sections. I will wait until #5437 is merged, and then I will open another PR. Thanks.