Pull request template

[rvi]

Hi,

I love this tool but unfortunately it doesn't take into account when there is a pull request template.

I'd love to be able to have pullRequestTemplatePath: "path/to/pull-request-template.md" in .spr.yml and inject the commit message in it.

For instance we could look for a variable like %%COMMIT_MESSAGE%% in the PR template and replace it. If we don't find this variable we could append the commit message at the end or the beginning of the template.

I can try to develop it but I'd like to know first if you're onboard with this idea. Let me know what you think!

Cheers.