Update phrasing of violation.

Author: Nurdok

src/pydocstyle/violations.py

@@ -219,7 +219,7 @@ def to_rst(cls) -> str:
 D400 = D4xx.create_error('D400', 'First line should end with a period',
                          'not {0!r}')
 D401 = D4xx.create_error('D401', 'First line should be in imperative mood',
-                         "'{0}', not '{1}'")
+                         "perhaps '{0}', not '{1}'")
 D401b = D4xx.create_error('D401', 'First line should be in imperative mood; '
                           'try rephrasing', "found '{0}'")
 D402 = D4xx.create_error('D402', 'First line should not be the function\'s '

src/tests/test_cases/noqa.py

@@ -16,7 +16,8 @@ def docstring_bad_ignore_one():  # noqa: D400,D401,D415
     pass
 
 
-@expect("D401: First line should be in imperative mood ('Run', not 'Runs')")
+@expect("D401: First line should be in imperative mood "
+        "(perhaps 'Run', not 'Runs')")
 def docstring_ignore_some_violations_but_catch_D401():  # noqa: E501,D400,D415
     """Runs something"""
     pass

src/tests/test_cases/sections.py

@@ -177,7 +177,7 @@ def ignore_non_actual_section():  # noqa: D416
 
 @expect(_D213)
 @expect("D401: First line should be in imperative mood "
-        "('Return', not 'Returns')")
+        "(perhaps 'Return', not 'Returns')")
 @expect("D400: First line should end with a period (not 's')")
 @expect("D415: First line should end with a period, question "
         "mark, or exclamation point (not 's')")

src/tests/test_cases/test.py

@@ -287,8 +287,8 @@ def lwnlkjl():
     """Summary"""
 
 
-@expect("D401: First line should be in imperative mood ('Return', not "
-        "'Returns')")
+@expect("D401: First line should be in imperative mood "
+        "(perhaps 'Return', not 'Returns')")
 def liouiwnlkjl():
     """Returns foo."""
 
@@ -361,7 +361,8 @@ def inner_function():
 
 
 @expect("D400: First line should end with a period (not 'g')")
-@expect("D401: First line should be in imperative mood ('Run', not 'Runs')")
+@expect("D401: First line should be in imperative mood "
+        "(perhaps 'Run', not 'Runs')")
 @expect("D415: First line should end with a period, question mark, "
         "or exclamation point (not 'g')")
 def docstring_bad():
@@ -379,7 +380,8 @@ def docstring_bad_ignore_one():  # noqa: D400,D401,D415
     pass
 
 
-@expect("D401: First line should be in imperative mood ('Run', not 'Runs')")
+@expect("D401: First line should be in imperative mood "
+        "(perhaps 'Run', not 'Runs')")
 def docstring_ignore_some_violations_but_catch_D401():  # noqa: E501,D400,D415
     """Runs something"""
     pass