Rename "master" branch to "main"?

[Joseph Myers]

On Tue, 30 Jun 2020, Carlos O'Donell via Libc-alpha wrote:

> My proposal would be to rename the development and current release branch:
> 
> * master -> main
> 
> * release/2.32/master -> release/2.32/main

Have you reviewed the git hooks and hook configuration to identify 
anything that special-cases master or branch names involving "master"?  
For example, configuration of which branches do or do not allow 
non-fast-forward pushes / merge commits / ...?

Do you have all the wiki updates that would be required prepared?  In 
particular, detailed instructions for updating existing clones that have 
branches tracking master?

-- 
Joseph S. Myers
joseph@codesourcery.com