Update plugin document to use python plugin instead of pip.

Author: djgoku

docs/app/docs/guides/plugins.md

@@ -32,7 +32,7 @@ Built-in plugins are available for the following packages. You can activate the
 * [Redis](../devbox_examples/databases/redis.md) (redis)
 * [Valkey](../devbox_examples/databases/valkey.md) (valkey)
 * [PHP](../devbox_examples/languages/php.md) (php, php80, php81, php82...)
-* [Pip](../devbox_examples/languages/python.md) (python39Packages.pip, python310Packages.pip, python311Packages.pip...)
+* [Python](../devbox_examples/languages/python.md) (python39Packages.pip, python310Packages.pip, python311Packages.pip...)
 * [Ruby](../devbox_examples/languages/ruby.md)(ruby, ruby_3_1, ruby_3_0...)