ADR Suggestion, Default branch naming

[AndrewSazonov]

Since the beginning of GitHub, the default branch name was set to master. Some time ago, GitHub renamed the default branch from master to main. At some point in the EasyScience organisation settings we changed it back to master.

As a result, some of our projects have default branches called master (e.g. EasyDiffraction, etc.) and others are called main (e.g. EasyReflectometry, etc.).

I propose to choose one or the other name and make it uniform for all repositories within the EasyScience organisation.

[rozyczko]

The reason it got switched to main in reflectometry was to fix a merge issue, where we saw backmerges not working properly.

I agree we should standardize on a single main repository and I also think it should be called master.

[AndrewSazonov]

So, the conclusion is to use master as the default branch name for the whole EasyScience organisation and to rename main to master in projects where this has not already been done.