yarn dev (#1208)

Procfile.start

@@ -0,0 +1,2 @@
+server: yarn start:server
+web: yarn start:client

README.md

@@ -12,20 +12,26 @@ To run Yari locally, you'll first need to install [git](https://git-scm.com/), [
     git clone https://github.com/mdn/yari.git
     cd yari
     yarn
-    yarn start
+    yarn dev
     open http://localhost:3000
 
 If you prefer, you can fork the repo first and do the `git clone` with
 _your_ fork instead of the `mdn` one.
 
+The `yarn dev` command will compile and prepare certain files. This always
+takes a little extra time. If you prefer you can use `yarn start` which
+will re-use any previously compiled files which is "riskier" but faster.
+The `yarn start` command will also start a server which doesn't automatically
+reload when its source code files change, so use with caution.
+
 ### How to stay up-to-date
 
 Periodically, the code and the content changes. Make sure you're staying
 up-to-date with these commands:
 
     git pull origin master
     yarn
-    yarn start
+    yarn dev
 
 These are also good steps to always take when you embark on making a change.
 Then, the only extra command needed is `git checkout -b my-new-branch`

package.json

@@ -15,8 +15,10 @@
     "build:ssr": "cd ssr && webpack --config webpack.config.js --mode=production",
     "prepare-build": "yarn build:client && yarn build:ssr",
     "build": "cd build && cross-env NODE_ENV=production node cli.js",
-    "start": "yarn build:client && yarn build:ssr && nf start",
+    "start": "(test -f client/build/index.html || yarn build:client) && (test -f ssr/dist/main.js || yarn build:ssr) && nf -j Procfile.start start",
+    "dev": "yarn build:client && yarn build:ssr && nf -j Procfile.dev start",
     "start:client": "cd client && cross-env BROWSER=none PORT=3000 react-scripts start",
+    "start:server": "node server",
     "start:dev-server": "nodemon server --watch server --watch build --watch content --watch kumascript",
     "start:static-server": "cross-env ENV_FILE=testing/.env node server/static.js",
     "filecheck": "cd filecheck && node cli.js"