ESLint parity with the Browsertrix repo (#288)

This copies the rules from the Browsertrix repo, and uses
[`suppress-eslint-errors`](https://www.npmjs.com/package/suppress-eslint-errors)
to suppose the violations. I'll take a pass at cleaning this up at some
point in the future, and let's do our best to address these in the
future as we come across them :)

This'll help ensure new code being added to this repo is held to the
same standard as code in Browsertrix's frontend.

src/misc.ts

@@ -104,6 +104,8 @@ class FaIcon extends LitElement {
       <g>
         ${
           // @ts-expect-error - TS2339 - Property 'svg' does not exist on type 'FaIcon'.
+          // TODO: Fix this the next time the file is edited.
+          // eslint-disable-next-line @typescript-eslint/no-unsafe-argument
           unsafeSVG(this.svg)
         }
       </g>