Remove mentions of Vetur extension and add Volar to .vscode recommendations

Author: abelsiqueira

.vscode/extensions.json

@@ -1,8 +1,8 @@
 {
   "recommendations": [
     "dbaeumer.vscode-eslint",
-    
-    "octref.vetur"
+
+    "Vue.volar"
   ],
   "unwantedRecommendations": [
     "hookyqr.beautify",

.vscode/settings.json

@@ -1,7 +1,4 @@
 {
-  "vetur.validation.template": false,
-  "vetur.format.enable": false,
   "eslint.validate": ["javascript", "javascriptreact", "typescript", "vue"],
-  "typescript.tsdk": "node_modules/typescript/lib",
-  "vetur.experimental.templateInterpolationService": true
+  "typescript.tsdk": "node_modules/typescript/lib"
 }

README.dev.md

@@ -10,7 +10,6 @@ If you are looking for user documentation, go [here](README.md).
 
 - VSCode extensions: https://code.visualstudio.com/
   - https://marketplace.visualstudio.com/items?itemName=Vue.volar
-  - https://marketplace.visualstudio.com/items?itemName=octref.vetur
   - https://marketplace.visualstudio.com/items?itemName=dbaeumer.vscode-eslint
 - WebStorm: https://www.jetbrains.com/webstorm/
 - Atom: https://atom.io/