feat: add modePicker config

Author: stevapple

components/Mode/ModePicker.vue

@@ -31,8 +31,9 @@ export default {
 
   mounted () {
     const mode = localStorage.getItem('mode')
-    const { mode: customizeMode } = this.$themeConfig
-    this.currentMode = mode ?? (customizeMode === null || customizeMode === undefined ? 'auto' : customizeMode)
+    const { mode: customizeMode, modePicker } = this.$themeConfig
+    const themeMode = customizeMode ?? 'auto'
+    this.currentMode = modePicker === false ? themeMode : mode ?? themeMode
     setMode(this.currentMode)
   },
 

components/Navbar.vue

@@ -22,7 +22,7 @@
         'max-width': linksWrapMaxWidth + 'px'
       } : {}">
 
-      <Mode v-show="$themeConfig.mode !== null" />
+      <Mode v-show="$themeConfig.modePicker !== false" />
       <AlgoliaSearchBox
         v-if="isAlgoliaSearch"
         :options="algolia"/>