Rename master to main

[lhoestq]

This PR renames mentions of "master" by "main" in the code base for several cases:

• set the default dataset script version to "main" if the local installation of datasets is a dev installation
• update URLs to this github repository to use "main"
• update the DVC benchmark
• update the github workflows
• update docstrings
• update tests to compare the changes in dataset cards against "main"

[HuggingFaceDocBuilderDev]

The documentation is not available anymore as the PR was closed or merged.

[albertvillanova]

Thank you. This was a pending task to do for too long...

I guess everything is right. The validation is a bit blindly. This is not a task we do often...

Do you know if some other projects may have our default branch name hard-coded?

[lhoestq]

All the mentions I found on google were simple URLs that will be redirected, so it's fine. I also checked the spaces and we should be good:

• dalle-mini used to install the master branch but it's no longer the case
• same for logo generator
• I opened a PR to fix vision-datasets-viewer

[lhoestq]

Ok let's rename the branch, and then we can merge this PR