Syncing `systematics_master.yml` on the cms-analysis.docs.cern.ch

Hi @lenzip, @anigamov, @kcormier,

There was some confusion by analyzers about which systematics_master.yml is the latest one, because it seems the version in the official instructions on cms-analysis.docs.cern.ch, is not the latest one because of recent changes?

https://cms-analysis.docs.cern.ch/guidelines/systematics/systematics/systematics_master.yml

I am wondering if from these instruction, we can link directly to the version on GitLab to keep it synced?

https://gitlab.cern.ch/cms-analysis/general/systematics/-/raw/master/systematics_master.yml?ref_type=heads (raw preview)