mark param extract_from: fix typos in docstring

Author: RonnyPfannschmidt

_pytest/mark.py

@@ -32,7 +32,8 @@ def extract_from(cls, parameterset, legacy_force_tuple=False):
             and may or may not be wrapped into a mess of mark objects
 
         :param legacy_force_tuple:
-          enforce tuple wrapping so single arugment tuple values dont get decomposed and break tests
+            enforce tuple wrapping so single argument tuple values
+            don't get decomposed and break tests
 
         """