docs: Better README.md for toHaveTextContent (#74)

Author: lourenci

.all-contributorsrc

@@ -195,7 +195,8 @@
       "avatar_url": "https://avatars3.githubusercontent.com/u/2339362?v=4",
       "profile": "https://blog.lourenci.com/",
       "contributions": [
-        "bug"
+        "bug",
+        "doc"
       ]
     }
   ]

README.md

@@ -626,32 +626,40 @@ The usual rules of css precedence apply.
 toHaveTextContent(text: string | RegExp, options?: {normalizeWhitespace: boolean})
 ```
 
-This API allows you to check whether the given element has a text content or not.
+This allows you to check whether the given element has a text content or not.
+
+When a `string` argument is passed through, it will perform a partial case-sensitive match to the element content.
+
+To perform a case-insensitive match, you can use a `RegExp` with the `/i` modifier.
+
+If you want to match the whole content, you can use a `RegExp` to do it.
 
 #### Examples
 
 ```html
-<span data-testid="count-value">2</span>
+<span data-testid="text-content">Text Content</span>
 ```
 
 ##### Using document.querySelector
 
 ```javascript
-const element = document.querySelector('[data-testid="count-value"]')
+const element = document.querySelector('[data-testid="text-content"]')
 
-expect(element).toHaveTextContent('2')
-expect(element).toHaveTextContent(/^2$/)
-expect(element).not.toHaveTextContent('21')
+expect(element).toHaveTextContent('Content')
+expect(element).toHaveTextContent(/^Text Content$/) // to match the whole content
+expect(element).toHaveTextContent(/content$/i) // to use case-insentive match
+expect(element).not.toHaveTextContent('content')
 ```
 
 ##### Using dom-testing-library
 
 ```javascript
-const element = getByTestId(container, 'count-value')
+const element = getByTestId(container, 'text-content')
 
-expect(element).toHaveTextContent('2')
-expect(element).toHaveTextContent(/^2$/)
-expect(element).not.toHaveTextContent('21')
+expect(element).toHaveTextContent('Content')
+expect(element).toHaveTextContent(/^Text Content$/) // to match the whole content
+expect(element).toHaveTextContent(/content$/i) // to use case-insentive match
+expect(element).not.toHaveTextContent('content')
 ```
 
 <hr />
@@ -728,7 +736,7 @@ Thanks goes to these people ([emoji key][emojis]):
 | [<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/gnapse/jest-dom/commits?author=kentcdodds "Code") [📖](https://github.com/gnapse/jest-dom/commits?author=kentcdodds "Documentation") [🚇](#infra-kentcdodds "Infrastructure (Hosting, Build-Tools, etc)") [⚠️](https://github.com/gnapse/jest-dom/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/gnapse/jest-dom/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/gnapse/jest-dom/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/gnapse/jest-dom/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/gnapse/jest-dom/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/gnapse/jest-dom/issues?q=author%3Apbomb "Bug reports") [💻](https://github.com/gnapse/jest-dom/commits?author=pbomb "Code") [📖](https://github.com/gnapse/jest-dom/commits?author=pbomb "Documentation") [⚠️](https://github.com/gnapse/jest-dom/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") |
 | :---: | :---: | :---: | :---: | :---: | :---: | :---: |
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-| [<img src="https://avatars1.githubusercontent.com/u/1659099?v=4" width="100px;"/><br /><sub><b>smacpherson64</b></sub>](https://github.com/smacpherson64)<br />[💻](https://github.com/gnapse/jest-dom/commits?author=smacpherson64 "Code") [📖](https://github.com/gnapse/jest-dom/commits?author=smacpherson64 "Documentation") [⚠️](https://github.com/gnapse/jest-dom/commits?author=smacpherson64 "Tests") | [<img src="https://avatars2.githubusercontent.com/u/132233?v=4" width="100px;"/><br /><sub><b>John Gozde</b></sub>](https://github.com/jgoz)<br />[🐛](https://github.com/gnapse/jest-dom/issues?q=author%3Ajgoz "Bug reports") [💻](https://github.com/gnapse/jest-dom/commits?author=jgoz "Code") | [<img src="https://avatars2.githubusercontent.com/u/7830590?v=4" width="100px;"/><br /><sub><b>Iwona</b></sub>](https://github.com/callada)<br />[💻](https://github.com/gnapse/jest-dom/commits?author=callada "Code") [📖](https://github.com/gnapse/jest-dom/commits?author=callada "Documentation") [⚠️](https://github.com/gnapse/jest-dom/commits?author=callada "Tests") | [<img src="https://avatars0.githubusercontent.com/u/840609?v=4" width="100px;"/><br /><sub><b>Lewis</b></sub>](https://github.com/6ewis)<br />[💻](https://github.com/gnapse/jest-dom/commits?author=6ewis "Code") | [<img src="https://avatars3.githubusercontent.com/u/2339362?v=4" width="100px;"/><br /><sub><b>Leandro Lourenci</b></sub>](https://blog.lourenci.com/)<br />[🐛](https://github.com/gnapse/jest-dom/issues?q=author%3Alourenci "Bug reports") |
+| [<img src="https://avatars1.githubusercontent.com/u/1659099?v=4" width="100px;"/><br /><sub><b>smacpherson64</b></sub>](https://github.com/smacpherson64)<br />[💻](https://github.com/gnapse/jest-dom/commits?author=smacpherson64 "Code") [📖](https://github.com/gnapse/jest-dom/commits?author=smacpherson64 "Documentation") [⚠️](https://github.com/gnapse/jest-dom/commits?author=smacpherson64 "Tests") | [<img src="https://avatars2.githubusercontent.com/u/132233?v=4" width="100px;"/><br /><sub><b>John Gozde</b></sub>](https://github.com/jgoz)<br />[🐛](https://github.com/gnapse/jest-dom/issues?q=author%3Ajgoz "Bug reports") [💻](https://github.com/gnapse/jest-dom/commits?author=jgoz "Code") | [<img src="https://avatars2.githubusercontent.com/u/7830590?v=4" width="100px;"/><br /><sub><b>Iwona</b></sub>](https://github.com/callada)<br />[💻](https://github.com/gnapse/jest-dom/commits?author=callada "Code") [📖](https://github.com/gnapse/jest-dom/commits?author=callada "Documentation") [⚠️](https://github.com/gnapse/jest-dom/commits?author=callada "Tests") | [<img src="https://avatars0.githubusercontent.com/u/840609?v=4" width="100px;"/><br /><sub><b>Lewis</b></sub>](https://github.com/6ewis)<br />[💻](https://github.com/gnapse/jest-dom/commits?author=6ewis "Code") | [<img src="https://avatars3.githubusercontent.com/u/2339362?v=4" width="100px;"/><br /><sub><b>Leandro Lourenci</b></sub>](https://blog.lourenci.com/)<br />[🐛](https://github.com/gnapse/jest-dom/issues?q=author%3Alourenci "Bug reports") [📖](https://github.com/gnapse/jest-dom/commits?author=lourenci "Documentation") |
 
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