feat(container.scss): add container styles for fixed position and scrolling behavior

feat(container.ts): create container module to handle scrollable behavior and add/remove disableScroll class

fix(customCursor.ts): update append target for cursor element to use container instead of main

fix(stage.ts): update append target for stage element to use container instead of main

fix(stageNav.ts): update append target for navOverlay element to use container instead of main

feat(main.ts): initialize container module and conditionally initialize stage and stageNav modules based on device type

fix(nav.ts): update references to state module functions to use state.get() instead of getState()

assets/ts/container.ts

@@ -0,0 +1,14 @@
+import { scrollable } from './mobile/scroll'
+
+export let container: HTMLDivElement
+
+export function initContainer(): void {
+  container = document.getElementsByClassName('container').item(0) as HTMLDivElement
+  scrollable.addWatcher(() => {
+    if (scrollable.get()) {
+      container.classList.remove('disableScroll')
+    } else {
+      container.classList.add('disableScroll')
+    }
+  })
+}