Document new @wordpress/scripts builder.

[x] Create blurb bragging about @wordpress/scripts integration and my build process.
[x] Review existing @wordpress/* import information.
[x] Remove any npm run clean or other deprecated actions.
[x] Double check file paths and folder/file organization.
[x] Remove all mention of Parcel and change to Webpack.
[x] Now supports scss (and ts) extensions.
[ ] Read through everything.

tcmulder / aquamin