Look for `scriv.ini` in parent directories

I'm looking to use scriv on a non-python project which contains several packages that each need their own changelogs. I can put a changelog.d directory in each package, which is fine, but if I want to configure scriv I need to put a scriv.ini in every changelog.d. If it was a python project I could put it in one of the python config files, but I'm not.

A simple solution would be to also look for scriv.ini in parent directories.

Example project layout:

scriv.ini
package-a/
  changelog.d
  ...
package-b/
  changelog.d
  ...

nedbat / scriv

Look for `scriv.ini` in parent directories #67