[GSoC] Microproject on git-credential-cache

Hi, everyone

I've been contributing to the Linux Kernel for the past semester and I'm now looking to take my first steps in the git community. I'm also interested in GSoC 2019.

I started looking at https://git.github.io/SoC-2019-Microprojects/ and one that got my attention was "Move ~/.git-credential-cache to ~/.cache/git". But looking around at the code and the mailing list, this microproject seems to have been already solved at 60759ba ("credential-cache: use XDG_CACHE_HOME for socket", 2017-03-17), right?

For the microproject "Add configuration options for some commonly used command-line options", are there some options already known to be good for adding to configuration file?

Finally, a non GSoC-related question. Just to confirm my understanding of Documentation/SubmittingPatches: I must send patches to the mailing list first and after some feedback from community, send to the maintainer with CC to the list, is that correct?

Thanks in advance, Matheus Tavares