Add extension suggestion for VSCode

.vscode/extensions.json

+{
+	"recommendations": [
+		"ducksoupdev.vue2",
+		"editorconfig.editorconfig",
+		"eg2.tslint",
+		"eg2.vscode-npm-script",
+		"hollowtree.vue-snippets",
+		"ms-vscode.typescript-javascript-grammar",
+		"octref.vetur",
+		"sysoev.language-stylus"
+	]
+}