Use 'git clone -b stable ...' in Getting Started instructions
Use 'git clone -b stable ...' in Getting Started instructions

This lets us switch the default branch back to master so PRs are
based properly but also avoids grabbing master before a release.

spotify/backup-utils,Teino1978-Corp/https-github.com-Teino1978-Corp-backup-utils,github/backup-utils,github/backup-utils