Fix URLs for 5.0.0 upgrade guide

Author: JohnHBrock

docs/warning_and_error_codes/W0500.md

@@ -3,7 +3,7 @@
 The W0500 error codes are reserved for warnings related to a major release of the isort project.
 Generally, the existence of any of these will trigger one additional warning listing the upgrade guide.
 
-For the most recent upgrade guide, see: [The 5.0.0 Upgrade Guide.](https://pycqa.github.io/isort/docs/upgrade_guides/5.0.0/).
+For the most recent upgrade guide, see: [The 5.0.0 Upgrade Guide.](https://pycqa.github.io/isort/docs/upgrade_guides/5.0.0.html).
 
 ## W0501: Deprecated CLI flags were included that will be ignored.
 

isort/main.py

@@ -137,8 +137,8 @@ def _build_arg_parser() -> argparse.ArgumentParser:
         "Use `-` as the first argument to represent stdin. Use --interactive to use the pre 5.0.0 "
         "interactive behavior."
         " "
-        "If you've used isort 4 but are new to isort 5, see the upgrading guide:"
-        "https://pycqa.github.io/isort/docs/upgrade_guides/5.0.0/.",
+        "If you've used isort 4 but are new to isort 5, see the upgrading guide: "
+        "https://pycqa.github.io/isort/docs/upgrade_guides/5.0.0.html",
         add_help=False,  # prevent help option from appearing in "optional arguments" group
     )
 
@@ -1230,7 +1230,7 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
             )
         warn(
             "W0500: Please see the 5.0.0 Upgrade guide: "
-            "https://pycqa.github.io/isort/docs/upgrade_guides/5.0.0/"
+            "https://pycqa.github.io/isort/docs/upgrade_guides/5.0.0.html"
         )
 
     if wrong_sorted_files:

isort/settings.py

@@ -484,7 +484,8 @@ def __init__(
                 warn(
                     "W0503: Deprecated config options were used: "
                     f"{', '.join(deprecated_options_used)}."
-                    "Please see the 5.0.0 upgrade guide: bit.ly/isortv5."
+                    "Please see the 5.0.0 upgrade guide: "
+                    "https://pycqa.github.io/isort/docs/upgrade_guides/5.0.0.html"
                 )
 
         if known_other: