Add parcel to the project

[nickytonline]

Parcel is web application bundler that out of the box has zero configuration.

Although we use webpack in the forem code base, it would be nice to consider a different more modern bundler. The main reason we use webpack in the Forem code base is because of it's integration with Rails via webpacker. It also ships with Rails 6.

In browser extension land, we do not have this constraint.

I have a proof of concept that I will post sometime this week as a draft PR to show how it all comes together.

Some benefits of adding a bundler to the extension code base:

• ES modules
• minification
• hot reloading

Let us know what you think about using Parcel.