feat(extension): recommend extensions

`extensions.recommendations`

src/extension/index.ts

@@ -80,6 +80,7 @@ export class Extensions {
     await this.manager.activateExtensions()
     let names = this.states.filterGlobalExtensions(workspace.env.globalExtensions)
     void this.installExtensions(names)
+    await this.promptRecommendedExtensions()
     // check extensions need watch & install
     let config = workspace.initialConfiguration.get('coc.preferences') as any
     let interval = config.extensionUpdateCheck
@@ -92,6 +93,17 @@ export class Extensions {
     }
   }
 
+  public async promptRecommendedExtensions(): Promise<void> {
+    const recommendations = workspace.getConfiguration('extensions', workspace.workspaceFolders[0]).get<string[]>('recommendations', [])
+    const unInstalled = this.states.filterGlobalExtensions(recommendations)
+    if (unInstalled.length) {
+      const toInstalls = await window.showPickerDialog(unInstalled, 'Install recommend extensions?')
+      if (toInstalls?.length) {
+        await this.installExtensions(toInstalls)
+      }
+    }
+  }
+
   public get onDidLoadExtension(): Event<Extension<API>> {
     return this.manager.onDidLoadExtension
   }