Add additional docs for uncooperative ctor deprecation (#9498)

* Add additional docs for uncooperative ctor deprecation

Fixes #9488

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Break up long line

* Recommend kwonly args

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

src/_pytest/nodes.py

@@ -145,7 +145,10 @@ class NodeMeta(type):
 
             warnings.warn(
                 PytestDeprecationWarning(
-                    f"{self} is not using a cooperative constructor and only takes {set(known_kw)}"
+                    f"{self} is not using a cooperative constructor and only takes {set(known_kw)}.\n"
+                    "See https://docs.pytest.org/en/stable/deprecations.html"
+                    "#constructors-of-custom-pytest-node-subclasses-should-take-kwargs "
+                    "for more details."
                 )
             )