Add documentation for messages with assert in their name (#5960)

Co-authored-by: Vladyslav Krylasov <[email protected]>
Co-authored-by: Pierre Sassoulas <[email protected]>

Author: 3 people

doc/data/messages/a/assert-on-string-literal/bad.py

@@ -0,0 +1,2 @@
+def test():
+    assert "There is an AssertionError"  # [assert-on-string-literal]

doc/data/messages/a/assert-on-string-literal/good.py

@@ -0,0 +1,2 @@
+def test():
+    # Nothing, as an assert of a string literal will always pass

doc/data/messages/a/assert-on-tuple/bad.py

@@ -0,0 +1 @@
+assert (1, None)  # [assert-on-tuple]

doc/data/messages/a/assert-on-tuple/good.py

@@ -0,0 +1,3 @@
+x, y = (1, None)
+assert x
+assert y

doc/data/messages/r/redundant-unittest-assert/bad.py

@@ -0,0 +1,6 @@
+import unittest
+
+
+class DummyTestCase(unittest.TestCase):
+    def test_dummy(self):
+        self.assertTrue("foo")  # [redundant-unittest-assert]

doc/data/messages/r/redundant-unittest-assert/good.py

@@ -0,0 +1,6 @@
+import unittest
+
+
+class DummyTestCase(unittest.TestCase):
+    def test_dummy(self):
+        # Nothing, as an assert of a string literal will always pass