docs: All uswds scss modules now applied in Storybook

[haworku]

Summary

Fix #191 and add comments in other stylesheet files to better explain whats happening.

Related Issues or PRs

resolves #191

How To Test

• Hover on footer nav links should show blue color (if not already visited). If your links have already been visited you may need to clear history for localhost.

[haworku]

Turning back to draft since Happo is showing some interesting discrepancies that I will look into more.

[haworku]

This ticket adds all USWDS scss to Storybook in order to use custom variables. However, the change is causing some components to break in certain browsers as seen in the Happo diff and the screenshot below. This seems like an autoprefixing issue.

Notes:

• UWSDS scss requires autoprefixing to work (see USWDS installation docs - Sass Compilation Requirements).
• We need to adjust Storybook webpack configuration to do this, for example by using autoprefixer and postcss-loader). It is a relatively a simple change, particularly since Storybook already includes the postcss-loader.
• However 😇 Storybook's version is of postcss-loader is out of date. It needs to be updated to version 8+ to work, which is well documented. So right now everything breaks when we add autoprefixing (see 3a14ad0 ).
• In the screenshot below the left side is the changes from this ticket, the right is whats on our live storybook. You can see the autoprefixing issue in the CSS
  

[haworku]

Closing as "won't fix" due to reasons described in #191