Introduce GitHub Action to check for conflicts in PRs.
Introduce GitHub Action to check for conflicts in PRs.

Alternative to adding this feature to coqbot (coq/bot#14).

SkySkimmer/coq,SkySkimmer/coq,ejgallego/coq,coq/coq,ejgallego/coq,SkySkimmer/coq,Zimmi48/coq,silene/coq,JasonGross/coq,JasonGross/coq,coq/coq,Zimmi48/coq,Zimmi48/coq,coq/coq,gares/coq,SkySkimmer/coq,silene/coq,JasonGross/coq,gares/coq,ejgallego/coq,ejgallego/coq,gares/coq,silene/coq,Zimmi48/coq,coq/coq,JasonGross/coq,gares/coq,gares/coq