Add httomo version comment to pipeline file copied to output dir

[yousefmoazzam]

Checklist

• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have made corresponding changes to the documentation

[yousefmoazzam]

The version comment in the copied pipeline YAML file has the following form:

# HTTomo version <VERSION>

As a reminder:

• for tagged commits (ie, releases) the version will be of the form x.y.z
• for other commits the version will be of the form x.y.z.postN, where N is the number of commits since the last tagged commit.

Feel free to suggest alternative wording for the comment 🙂