Add yarn clean command

package.json

@@ -45,12 +45,14 @@
         "@types/node": "^14.6.4",
         "ajv": "^6.12.4",
         "npm-run-all": "^4.1.5",
+        "rimraf": "^3.0.2",
         "ts-node": "^9.0.0",
         "typescript": "^4.0.2",
         "vsce": "^1.79.5",
         "vscode-tmgrammar-test": "0.0.10"
     },
     "scripts": {
+        "clean": "rimraf scala-*.vsix",
         "vscode:prepublish": "test -f ./syntaxes/Scala.tmLanguage.json",
         "vscode:publish": "vsce publish --yarn",
         "build": "npm-run-all build:syntax build:extension",

yarn.lock

@@ -298,7 +298,7 @@ glob@^7.0.6:
     once "^1.3.0"
     path-is-absolute "^1.0.0"
 
-glob@^7.1.6:
+glob@^7.1.3, glob@^7.1.6:
   version "7.1.6"
   resolved "https://registry.yarnpkg.com/glob/-/glob-7.1.6.tgz#141f33b81a7c2492e125594307480c46679278a6"
   integrity sha512-LwaxwyZ72Lk7vZINtNNrywX0ZuLyStrdDtabefZKAY5ZGJhVtgdznluResxNmPitE0SAO+O26sWTHeKSI2wMBA==
@@ -671,6 +671,13 @@ resolve@^1.10.0:
   dependencies:
     path-parse "^1.0.6"
 
+rimraf@^3.0.2:
+  version "3.0.2"
+  resolved "https://registry.yarnpkg.com/rimraf/-/rimraf-3.0.2.tgz#f1a5402ba6220ad52cc1282bac1ae3aa49fd061a"
+  integrity sha512-JZkJMZkAGFFPP2YqXZXPbMlMBgsxzE8ILs4lMIX/2o0L9UBw9O/Y3o6wFw/i9YLapcUJWwqbi3kdxIPdC62TIA==
+  dependencies:
+    glob "^7.1.3"
+
 safe-buffer@~5.1.0:
   version "5.1.2"
   resolved "https://registry.yarnpkg.com/safe-buffer/-/safe-buffer-5.1.2.tgz#991ec69d296e0313747d59bdfd2b745c35f8828d"