docs: update readme for getByLabelText (#24)

Author: Jonah Moses

.all-contributorsrc

@@ -76,6 +76,15 @@
       "contributions": [
         "platform"
       ]
+    },
+    {
+      "login": "JonahMoses",
+      "name": "Jonah Moses",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/3462296?v=4",
+      "profile": "https://github.com/JonahMoses",
+      "contributions": [
+        "doc"
+      ]
     }
   ]
 }

README.md

@@ -16,7 +16,7 @@
 [![downloads][downloads-badge]][npmtrends]
 [![MIT License][license-badge]][license]
 
-[![All Contributors](https://img.shields.io/badge/all_contributors-7-orange.svg?style=flat-square)](#contributors)
+[![All Contributors](https://img.shields.io/badge/all_contributors-8-orange.svg?style=flat-square)](#contributors)
 [![PRs Welcome][prs-badge]][prs]
 [![Code of Conduct][coc-badge]][coc]
 
@@ -171,7 +171,7 @@ const inputNode = getByLabelText('Username')
 // <label><span>Username</span> <input /></label>
 //
 // For this case, you can provide a `selector` in the options:
-const inputNode = getByLabelText('username-input', {selector: 'input'})
+const inputNode = getByLabelText('username', {selector: 'input'})
 // and that would work
 ```
 
@@ -564,6 +564,7 @@ Thanks goes to these people ([emoji key][emojis]):
 <!-- prettier-ignore -->
 | [<img src="https://avatars.githubusercontent.com/u/1500684?v=3" width="100px;"/><br /><sub><b>Kent C. Dodds</b></sub>](https://kentcdodds.com)<br />[💻](https://github.com/kentcdodds/react-testing-library/commits?author=kentcdodds "Code") [📖](https://github.com/kentcdodds/react-testing-library/commits?author=kentcdodds "Documentation") [🚇](#infra-kentcdodds "Infrastructure (Hosting, Build-Tools, etc)") [⚠️](https://github.com/kentcdodds/react-testing-library/commits?author=kentcdodds "Tests") | [<img src="https://avatars1.githubusercontent.com/u/2430381?v=4" width="100px;"/><br /><sub><b>Ryan Castner</b></sub>](http://audiolion.github.io)<br />[📖](https://github.com/kentcdodds/react-testing-library/commits?author=audiolion "Documentation") | [<img src="https://avatars0.githubusercontent.com/u/8008023?v=4" width="100px;"/><br /><sub><b>Daniel Sandiego</b></sub>](https://www.dnlsandiego.com)<br />[💻](https://github.com/kentcdodds/react-testing-library/commits?author=dnlsandiego "Code") | [<img src="https://avatars2.githubusercontent.com/u/12592677?v=4" width="100px;"/><br /><sub><b>Paweł Mikołajczyk</b></sub>](https://github.com/Miklet)<br />[💻](https://github.com/kentcdodds/react-testing-library/commits?author=Miklet "Code") | [<img src="https://avatars3.githubusercontent.com/u/464978?v=4" width="100px;"/><br /><sub><b>Alejandro Ñáñez Ortiz</b></sub>](http://co.linkedin.com/in/alejandronanez/)<br />[📖](https://github.com/kentcdodds/react-testing-library/commits?author=alejandronanez "Documentation") | [<img src="https://avatars0.githubusercontent.com/u/1402095?v=4" width="100px;"/><br /><sub><b>Matt Parrish</b></sub>](https://github.com/pbomb)<br />[🐛](https://github.com/kentcdodds/react-testing-library/issues?q=author%3Apbomb "Bug reports") [💻](https://github.com/kentcdodds/react-testing-library/commits?author=pbomb "Code") [📖](https://github.com/kentcdodds/react-testing-library/commits?author=pbomb "Documentation") [⚠️](https://github.com/kentcdodds/react-testing-library/commits?author=pbomb "Tests") | [<img src="https://avatars1.githubusercontent.com/u/1288694?v=4" width="100px;"/><br /><sub><b>Justin Hall</b></sub>](https://github.com/wKovacs64)<br />[📦](#platform-wKovacs64 "Packaging/porting to new platform") |
 | :---: | :---: | :---: | :---: | :---: | :---: | :---: |
+| [<img src="https://avatars2.githubusercontent.com/u/3462296?v=4" width="100px;"/><br /><sub><b>Jonah Moses</b></sub>](https://github.com/JonahMoses)<br />[📖](https://github.com/kentcdodds/react-testing-library/commits?author=JonahMoses "Documentation") |
 
 <!-- ALL-CONTRIBUTORS-LIST:END -->