Add notes list toggle shortcut (#145)

Reviewed-on: https://codeberg.org/ArkHost/HelixNotes/pulls/145

src/lib/components/NoteList.svelte

@@ -12,6 +12,7 @@
 		editorDirty,
 		quickAccessPaths,
 		appConfig,
+		notelistCollapsed,
 		notebooks,
 		tags,
 		mobileView
@@ -861,6 +862,16 @@
 	<div class="list-header">
 		<span class="list-title">{viewTitle}</span>
 		<div class="list-actions">
+			{#if !isMobile}
+				<button class="icon-btn" onclick={() => ($notelistCollapsed = true)} title={`Hide notes list (${modKey}+Shift+\\)`} aria-label="Hide notes list">
+					<svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+						<line x1="4" y1="6" x2="16" y2="6" />
+						<line x1="4" y1="12" x2="16" y2="12" />
+						<line x1="4" y1="18" x2="16" y2="18" />
+						<polyline points="19 8 21 12 19 16" />
+					</svg>
+				</button>
+			{/if}
 			{#if $viewMode !== 'tasks'}
 			{#if isAndroid}
 				<button class="icon-btn" class:active-toggle={multiSelectMode} onclick={() => { multiSelectMode = !multiSelectMode; if (!multiSelectMode) clearSelection(); }} title="Multi-select">