breaking(ui-shell): remove GlobalHeader, SideNav folders (#1223)

* breaking(ui-shell): remove GlobalHeader/SideNav folders

* Run "yarn build:docs"

src/UIShell/HamburgerMenu.svelte

@@ -0,0 +1,45 @@
+<script>
+  /**
+   * Specify the ARIA label for the button
+   * @type {string}
+   */
+  export let ariaLabel = undefined;
+
+  /** Set to `true` to toggle the open state */
+  export let isOpen = false;
+
+  /**
+   * Specify the icon to render for the closed state
+   * Defaults to `Menu20`
+   * @type {typeof import("svelte").SvelteComponent}
+   */
+  export let iconMenu = Menu20;
+
+  /**
+   * Specify the icon to render for the opened state
+   * Defaults to `Close20`
+   * @type {typeof import("svelte").SvelteComponent}
+   */
+  export let iconClose = Close20;
+
+  /** Obtain a reference to the HTML button element */
+  export let ref = null;
+
+  import Close20 from "../icons/Close20.svelte";
+  import Menu20 from "../icons/Menu20.svelte";
+</script>
+
+<button
+  bind:this="{ref}"
+  type="button"
+  title="{ariaLabel}"
+  aria-label="{ariaLabel}"
+  class:bx--header__action="{true}"
+  class:bx--header__menu-trigger="{true}"
+  class:bx--header__menu-toggle="{true}"
+  {...$$restProps}
+  on:click
+  on:click="{() => (isOpen = !isOpen)}"
+>
+  <svelte:component this="{isOpen ? iconClose : iconMenu}" />
+</button>