Support templates for branch names

[micah-mtklabs]

When using the issue viewer to create/checkout a branch, I'd like to be able to adjust the template that's used. Currently, it's

{github-user}/issue{issue-number}

I want to be able to customize that.

[micah-mtklabs]

It seems like maybe there's code to support that, but I don't know enough about VS Code extensions to really understand it.

https://github.com/microsoft/vscode-pull-request-github/blob/main/src/issues/currentIssue.ts#L158-L163

[alexr00]

This already exists. See the setting githubIssues.issueBranchTitle.

[micah-mtklabs]

Sweet! I looked for that, but didn't find it, for some reason. 👍