vscode versions to v1.31.0, add collapes all. (#197)

Author: ZainChen

package-lock.json

@@ -8,7 +8,7 @@
     "license": "MIT",
     "icon": "resources/LeetCode.png",
     "engines": {
-        "vscode": "^1.23.0"
+        "vscode": "^1.30.1"
     },
     "repository": {
         "type": "git",

package.json

@@ -35,7 +35,7 @@ export async function activate(context: vscode.ExtensionContext): Promise<void>
         leetCodeStatusBarItem,
         leetCodeChannel,
         leetCodeResultProvider,
-        vscode.window.registerTreeDataProvider("leetCodeExplorer", leetCodeTreeDataProvider),
+        vscode.window.createTreeView("leetCodeExplorer", { treeDataProvider: leetCodeTreeDataProvider, showCollapseAll: true }),
         vscode.languages.registerCodeLensProvider({ scheme: "file" }, codeLensProvider),
         vscode.commands.registerCommand("leetcode.deleteCache", () => cache.deleteCache()),
         vscode.commands.registerCommand("leetcode.toggleLeetCodeCn", () => plugin.switchEndpoint()),