Makefile: Read user_config by path

[mk-pmb]

• This PR is for the dev branch rather than for master.
• This PR is compliant with the other contributing guidelines as well (if not, please describe why).
• I have thoroughly tested my contribution.
• The code changes are reflected in the documentation at docs/*.

Disclosing the true path allows for relative includes in user_config.

[TerryE]

As I said in the issue, I don't really want to dick around with something that we want to remove.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[mk-pmb]

Will the removal happen soon? Otherwise, let's help people deal with the status quo until we can really remove it.

[HHHartmann]

The relevant issue would be #1223? How could I include my own configs after this PR?
As I would not only have my own user_config but also user_modules and user_version would this PR suffice for that too?

[mk-pmb]

The relevant issue would be …?

I don't know if that issue is related in any way.
The issue I had, and caused me to write this patch, does not have a thread, as to me it didn't seem worth explaining. In my opinion, the opposite would be true: The current approach of concealing the filename would need a justification, and thus, documentation.

How could I include my own configs after this PR?

I expect that all previous workflows continue to work. That is, I hope no-one has relied on using relative file paths in their config in the current scenario where these paths would be calculated based on an expressly concealed origin.

As I would not only have my own user_config but also user_modules and user_version would this PR suffice for that too?

I don't understand the question, sorry.
Easiest way to check would probably be to temporarily patch this into your local repo and retry.