Fix docs for --isolated flag

docs/source/manpage.rst

@@ -88,7 +88,7 @@ All options available as of Flake8 3.1.0::
     --config=CONFIG       Path to the config file that will be the authoritative
                           config source. This will cause Flake8 to ignore all
                           other configuration files.
-    --isolated            Ignore all found configuration files.
+    --isolated            Ignore all configuration files.
     --benchmark           Print benchmark information about this run of Flake8
     --bug-report          Print information necessary when preparing a bug
                           report

docs/source/user/invocation.rst

@@ -138,7 +138,7 @@ And you should see something like:
       --config=CONFIG       Path to the config file that will be the authoritative
                             config source. This will cause Flake8 to ignore all
                             other configuration files.
-      --isolated            Ignore all found configuration files.
+      --isolated            Ignore all configuration files.
       --builtins=BUILTINS   define more built-ins, comma separated
       --doctests            check syntax of the doctests
       --include-in-doctest=INCLUDE_IN_DOCTEST

src/flake8/main/options.py

@@ -207,7 +207,7 @@ def register_default_options(option_manager):
 
     add_option(
         '--isolated', default=False, action='store_true',
-        help='Ignore all found configuration files.',
+        help='Ignore all configuration files.',
     )
 
     # Benchmarking