Re-generate manifest from script

Enacts formatting and ordering changes on manifest.json
It's good to run this script once in a while, as the manifest accrues
pecularities due to people manually adding specs; this enables future
users to run the script to add their own specs without introducing
irrelevant changes.

Signed-off-by: Andrew Helwer <ahelwer@pm.me>

Author: ahelwer