Rename 'master' branch

[matthias-ronge]

It is a trend in Git to rename all “master” branches to something else, usually “main”. The background is that, in English, the master word has the connotation of a lord, in the sense of slave driver. Personally, as a German speaker, I don’t read it that way, for me it's more like masterly, and that's probably what it was meant to be. But political correctness always means: not saying things that someone who is stupid, or who deliberately tries to misunderstand the other, might say, it was meant that way. So, if we do this, we will be paying tribute to many former slaves in the English-speaking part of the world or their descendants, so I would like to suggest such a change.

For all co-developers in Git, you might have to adjust the configuration a little.

[stweil]

I support this renaming (and did it already for other repositories, for example all repositories of https://github.com/tesseract-ocr/).

The rename process is easy, but can only be done by a maintainer. And of course it should be announced before it is done. When would be a good time for it? Maybe now?