Added to main bucket: https://github.com/ScoopInstaller/Main/blob/master/bucket/scc.json

I no longer use this application, and the move to YouTube Music leaves
its future uncertain.

I no longer use Pomotroid and am not interested in keeping the manifest
up to date.

This commit also adjusts the method for checking versions for Closure
Compiler. The GitHub repository does not have the latest release
correctly tagged, so I switched to a regular expression linked to the
releases page.

This commit fixes a small bug with the regular expression used to check
the version for Multiscreen Blank. It previously had an unescaped
period, allowing for any value instead of actual periods.

This commit adjusts the naming for Multiscreen Blank, which seems to
have dropped the v2 from it's official name. The landing page and
description for the program have also been changed. Note that this
version number may be incorrect; the website lists it as 2.3.1 but the
files reference it as 2.3.0.1.

This commit moves the manifests into a folder and adds a README file
containing the list of manifests and the purpose of the repository.