git start -i ISSUE_ID should auto append `-#ISSUE_ID` to branch name

[wireframe]

waffle can automatically update issue status when it detects a branch name with a matching issue id.
https://github.com/waffleio/waffle.io/wiki/Recommended-Workflow-Using-Pull-Requests-&-Automatic-Work-Tracking

NOTE: the branch name must have the # character and not just the issue id.