docs: add rebase instructions to commit command

.opencode/command/commit.md

@@ -21,3 +21,6 @@ WHAT was done.
 
 do not do generic messages like "improved agent experience" be very specific
 about what user facing changes were made
+
+if there are changes do a git pull --rebase
+if there are conflicts DO NOT FIX THEM. notify me and I will fix them