Options ui (#222)

* wip

* Commenting stuff to keep the build happy

* Revealing sections

* Custom select elements & more form work

* Range input styles

* Text fields with inputs do the right thing

* Safari & Firefox fixes

* Large compress select

* oops

* MozJPEG options updated

* OptPNG options

* These asserts weren't true

* Generic options

* WebP options

* Hiding "edit" when "original image"

* Download icon

* Copy setting button - still not happy with this

* Progress indicator

* Loading icon enter/exit anim

* Preventing controls going under options

* Ahh so that's what was causing scrolling

* Ahh so that's what was causing outlines

* Simplifying range styles and fixing cross-browser

* Processing custom element styles

* Get precision from step by default

* I don't know how or when this happened.

* Don't need that many steps

* Avoid having an element that covers the pinch zoom

* Preventing overlap with zoom controls

* Prevent ts warning

* Fixing spinner position

* Simplifying FileSize

src/components/checkbox/style.scss

@@ -0,0 +1,22 @@
+.checkbox {
+  display: inline-block;
+  position: relative;
+  --size: 17px;
+}
+
+.real-checkbox {
+  top: 0;
+  position: absolute;
+  opacity: 0;
+  pointer-events: none;
+}
+
+.icon {
+  display: block;
+  width: var(--size);
+  height: var(--size);
+}
+
+.checked {
+  fill: #34B9EB;
+}