Update docs about long-lived branches
Update docs about long-lived branches

spurti-chopra/travis-cookbooks,travis-ci/travis-cookbooks,ljharb/travis-cookbooks,travis-ci/travis-cookbooks,ljharb/travis-cookbooks,spurti-chopra/travis-cookbooks,travis-ci/travis-cookbooks,spurti-chopra/travis-cookbooks,ljharb/travis-cookbooks