Correct docs on which .env.* files are supported. (#2247)

* Correct which .env. files are referenced in docs

* Highlight this is not available until 1.0.0

* Formatting

* Update README.md

* Update README.md

packages/react-scripts/template/README.md

@@ -794,20 +794,20 @@ REACT_APP_SECRET_CODE=abcdef
 
 `.env` files **should be** checked into source control (with the exclusion of `.env*.local`).
 
-What other `.env` files are can be used?
+#### What other `.env` files are can be used?
 
->Note: this feature is available with `react-scripts@1.0.0` and higher.
+>Note: this feature is **available with `react-scripts@1.0.0` and higher**.
 
-* `.env` - Default
-* `.env.development`, `.env.test`, `.env.production` - Environment-specific settings.
-* `.env.local` - Local overrides. This file is loaded for all environments except test.
-* `.env.development.local`, `.env.test.local`, `.env.production.local` - Local overrides of environment-specific settings.
+* `.env`: Default.
+* `.env.local`: Local overrides. **This file is loaded for all environments except test.**
+* `.env.development`, `.env.test`, `.env.production`: Environment-specific settings.
+* `.env.development.local`, `.env.test.local`, `.env.production.local`: Local overrides of environment-specific settings.
 
-File priority, from left to right:
+Files on the left have more priority than files on the right:
 
-* npm test - `.env.test.local`, `env.test`, `.env.local`, `.env`
-* npm run build - `.env.production.local`, `env.production`, `.env.local`, `.env`
-* npm start - `.env.development.local`, `env.development`, `.env.local`, `.env`
+* `npm start`: `.env.development.local`, `.env.development`, `.env.local`, `.env`
+* `npm run build`: `.env.production.local`, `.env.production`, `.env.local`, `.env`
+* `npm test`: `.env.test.local`, `.env.test`, `.env` (note `.env.local` is missing)
 
 These variables will act as the defaults if the machine does not explicitly set them.<br>
 Please refer to the [dotenv documentation](https://github.com/motdotla/dotenv) for more details.