syntax/git-rebase-todo.yaml: support more commands (#2495)

For reference, see the list of supported commands in the help text of git's interactive rebase:
https://github.com/git/git/blob/v2.37.1/rebase-interactive.c#L43-L59

runtime/syntax/git-rebase-todo.yaml

@@ -5,7 +5,7 @@ detect:
 
 rules:
     # Rebase commands
-    - statement: "^(p(ick)?|r(eword)?|e(dit)?|s(quash)?|f(ixup)?|x|exec|d(rop)?)\\b"
+    - statement: "^(p(ick)?|r(eword)?|e(dit)?|s(quash)?|f(ixup)?|x|exec|b(reak)?|d(rop)?|l(abel)?|t|reset|m(erge)?)\\b"
     # Commit IDs
     - identifier: "\\b([0-9a-f]{7,40})\\b"