Update GIF encoding information

[raygard]

Correct Handbook documentation about encoding of GIF files from run-length to LZW.

No issue associated with this pull request.

Changes proposed in this pull request:

• Pillow writes GIF files with LZW encoding since 8.2.0, but the Handbook was not updated to reflect this. It still refers to run-length encoding (which was not quite correct before).

[radarhere]

Just to link issues - the LZW change occurred in #5291

[raygard]

@radarhere I need a little help. Not sure if this is the place to ask. I haven't done a pull in a year and I'm rusty. Contribution guidelines say "When committing only documentation changes please include [ci skip] in the commit message..." to avoid CI running. Looks like tests ran; did I put it in the wrong place or misunderstand? Also, I forked, got a local repo on my machine, and forgot to make a branch and make the change there instead of in the main branch. (Not even sure if I'm using the right words there.) Can this be fixed somehow? If I nuke my fork and re-fork, will my pull get messed up or deleted? I started small w/ this doc change but am working on some GIF plugin code changes. Would like that to be done exactly right. Any advice before I screw it up? If this is the wrong venue, email me at raygard at gmail dot com.

[radarhere]

Perfectly fine to ask here.

I think the simple answer is that you didn't include '[ci skip]' in the commit message. I don't see the text '[ci skip]' in your commit - https://github.com/raygard/Pillow/commit/b01a2effd2a719fb094bcef7c471b05c07c48dfa. You have included it in the PR title, but that's not the same thing.

I don't think the fact that you've made this change in your main branch is a problem necessarily, just not quite as neat as you might like.
My memory is that if you delete your fork, this pull request will actually be fine - but you don't need to go to that extreme. You could just git reset --hard HEAD^ your local main branch to bring it back in line with our main, leave the remote main branch as it is, and fork off from your local main branch.

[radarhere]

Or, if I just quickly merge this branch, then you can git pull python-pillow main, and fast forward to be back in line with our main.

[raygard]

Thanks for setting me straight on the [ci skip]. I just now used the "Fetch upstream" button on the web page for my fork and I think I'm in sync now. I had used git CLI last year but I forgot what little I knew about it then. I'm using the GitHub Desktop app in Windows for now and it's doing what I need... for now.