Reorganize branches

[Fryguy]

At one point, GitHub required the master branch for a .github.io repo to have what would be deployed by GitHub Pages. That has since changed, and we can have any branch we want. As such, we should reorganize the branches to be more expected. I propose:

• master -> gh-pages
• build -> master
• Update the default branch
• Update the settings to use gh-pages instead
• Update the deploy script to use gh-pages:

  manageiq.github.io/bin/deploy

  Line 12 in eff1c60

  git clone --bare --branch master --depth 5 https://x-access-token:${GITHUB_TOKEN}@github.com/ManageIQ/manageiq.github.io .git

[kbrock]

I know tooling will be an issue if we get away from master, but for this repo, it may be time to rename master to main.

Or keep the build branch as build?

[Fryguy]

I'm good with main. We could also keep build, but it's very confusing to people who get into this repo the first time, which is part of my reasoning for going to a "normal" default branch name.

I know tooling will be an issue if we get away from master

In this particular case it won't matter because we don't have tooling on this repo.