Speed up yarn dev TypeScript transpilation

Gruntfile.js

@@ -116,10 +116,6 @@ module.exports = grunt => {
         files: ['./stylesheets/*.scss', './stylesheets/**/*.scss'],
         tasks: ['sass'],
       },
-      transpile: {
-        files: ['./ts/**/*.ts', './ts/**/*.tsx'],
-        tasks: ['exec:transpile'],
-      },
     },
     exec: {
       'tx-pull-new': {

package.json

@@ -42,6 +42,7 @@
     "ready": "npm-run-all --print-label clean-transpile grunt --parallel lint lint-deps test-node test-electron",
     "dev": "run-p --print-label dev:*",
     "dev:grunt": "yarn grunt dev",
+    "dev:transpile": "yarn run transpile --watch --preserveWatchOutput",
     "dev:webpack": "cross-env NODE_ENV=development webpack-dev-server --hot",
     "dev:typed-scss": "yarn build:typed-scss -w",
     "dev:storybook": "cross-env SIGNAL_ENV=storybook start-storybook -p 6006 -s ./",