Update index.md

Bump up disk requirements to 12 GB.

Author: lstein

docs/index.md

@@ -86,7 +86,7 @@ You wil need one of the following:
 
 ### :fontawesome-regular-hard-drive: Disk
 
-- At least 6 GB of free disk space for the machine learning model, Python, and all its dependencies.
+- At least 12 GB of free disk space for the machine learning model, Python, and all its dependencies.
 
 !!! note