make warning comment more copyable

_CoqProject

 -Q theories iris
-# We sometimes want to locally override notation (e.g. in proofmode/base.v,
-# bi/embedding.v), and there is no good way to do that with scopes.
+# We sometimes want to locally override notation, and there is no good way to do that with scopes.
 -arg -w -arg -notation-overridden
 # Cannot use non-canonical projections as it causes massive unification failures
 # (https://github.com/coq/coq/issues/6294).