Option to skip uploading changelog

[p3lim]

I specifically need this for GitHub releases, but for all three would be good too.

[kemayo]

As a workaround, I wound up building a manual changelog and then using a tool to slice out just the current release's changes to use as the packager-changelog. This gets me decent GitHub release notes... at the cost of overwriting my WoWI changelog with only the current release. So, yeah, it's not perfect.

[p3lim]

I make my own changelogs in markdown format, ended up just trimming the changelog down to the first header and paragraph(s).

- name: Trim changelog
  run: sed -ni '1p;2,/^###/{/^###/q;p;}' CHANGELOG.md

If you want to close the issue that's fine by me, I'm satisfied with this.

[teelolws]

Actually I'd like this, an option to not include the changelog.md in the file. I still like the changelog it writes for the description fields, though.