(#392) Update safelist for community

[st3phhays]

Description Of Changes

This updates the safelist for the community repository when PurgeCSS is
ran. Before, we were able to look at the node_modules folder to compare
content, but now that most libraries are dev dependencies of
choco-theme, they are not installed on each repository. In this case,
they are no longer there to be looked at. The fix for this is to,
instead look at the source CSS, to find the top level CSS locater and
add it to the safelist of things not to be purged. By doing this, all
the necessary CSS shows up in the final purged CSS file.

Motivation and Context

The changes here a necessary for Community to look correct.

Testing

1. Ran CCR
2. Opened and used the search box to ensure all styles showed
3. Used the Editor on /packages to ensure all styles showed

Operating Systems Testing

n/a

Change Types Made

• Bug fix (non-breaking change).
• Feature / Enhancement (non-breaking change).
• Breaking change (fix or feature that could cause existing functionality to change).
• Documentation changes.
• PowerShell code changes.

Change Checklist

• Requires a change to the documentation.
• Documentation has been updated.
• Tests to cover my changes, have been added.
• All new and existing tests passed?
• PowerShell code changes: PowerShell v2 compatibility checked?

Related Issue

#392

[gep13]

LGTM!

[gep13]

@st3phhays thanks for getting this fixed up!