Add documentation for --disable-openapi CLI flag (#2082)

* Update installation.mdx

* Update installation.mdx

* Update api-playground/openapi-setup.mdx

* Update api-playground/openapi-setup.mdx

* Update api-playground/openapi-setup.mdx

* move info to CLI page

* copyedit

---------

Co-authored-by: mintlify[bot] <109931778+mintlify[bot]@users.noreply.github.com>
Co-authored-by: Ethan Palm <56270045+ethanpalm@users.noreply.github.com>

Author: mintlify[bot]

installation.mdx

@@ -67,6 +67,14 @@ If you attempt to run on a port that is already in use, it will use the next ava
 Port 3000 is already in use. Trying 3001 instead.
 ```
 
+## Skip OpenAPI processing
+
+If you have many OpenAPI files, skip OpenAPI file processing during local development to improve performance by using the `--disable-openapi` flag:
+
+```bash
+mint dev --disable-openapi
+```
+
 ### Preview as a specific group
 
 If you use partial authentication to restrict access to your documentation, you can preview as a specific authentication group by using the `--groups [groupname]` flag.