Add docs

.all-contributorsrc

@@ -6,5 +6,22 @@
   ],
   "imageSize": 100,
   "commit": false,
-  "contributors": []
+  "contributors": [
+    {
+      "login": "mattphillips",
+      "name": "Matt Phillips",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/5610087?v=4",
+      "profile": "http://mattphillips.io",
+      "contributions": [
+        "code",
+        "doc",
+        "example",
+        "ideas",
+        "infra",
+        "test",
+        "tool"
+      ]
+    }
+  ],
+  "repoType": "github"
 }

README.md

@@ -1,6 +1,8 @@
 <div align="center">
 <h1>jest-expect-message</h1>
 
+🃏🗯
+
 Add custom message to Jest expects
 </div>
 
@@ -14,10 +16,52 @@ Add custom message to Jest expects
 [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg?style=flat-square)](http://makeapullrequest.com)
 [![Roadmap](https://img.shields.io/badge/%F0%9F%93%94-roadmap-CD9523.svg?style=flat-square)](https://github.com/mattphillips/jest-expect-message/blob/master/docs/ROADMAP.md)
 [![Examples](https://img.shields.io/badge/%F0%9F%92%A1-examples-ff615b.svg?style=flat-square)](https://github.com/mattphillips/jest-expect-message/blob/master/docs/EXAMPLES.md)
+
 ## Problem
 
+In many testing libraries it is possible to supply a custom message for a given expectation, this is currently not
+possible in Jest.
+
+For example:
+
+```js
+test('returns 2 when adding 1 and 1', () => {
+  expect(1 + 1, 'Woah this should be 2!').toBe(3);
+});
+```
+
+This will throw the following error in Jest:
+
+```sh
+Expect takes at most one argument.
+```
+
 ## Solution
 
+`jest-expect-message` allows you to call `expect` with a second argument of a `String` message.
+
+For example the same test as above:
+
+```js
+test('returns 2 when adding 1 and 1', () => {
+  expect(1 + 1, 'Woah this should be 2!').toBe(3);
+});
+```
+
+With `jest-expect-message` this will fail with your custom error message:
+
+```sh
+  ● returns 2 when adding 1 and 1
+
+    Custom message:
+      Woah this should be 2!
+
+    expect(received).toBe(expected) // Object.is equality
+
+    Expected: 3
+    Received: 2
+```
+
 ## Installation
 
 With npm:
@@ -32,11 +76,33 @@ yarn add -D jest-expect-message
 
 ## Setup
 
+Add `jest-expect-message` to your Jest `setupTestFrameworkScriptFile` configuration.
+[See for help](https://facebook.github.io/jest/docs/en/configuration.html#setuptestframeworkscriptfile-string)
+
+```json
+"jest": {
+  "setupTestFrameworkScriptFile": "jest-expect-message"
+}
+```
+
 ## Usage
 
+ - `expect(actual, message)`
+   - `actual`: The value you would normally pass into an `expect` to assert against with a given matcher.
+   - `message`: String, the custom message you want to be printed should the `expect` fail.
+
+```js
+test('returns 2 when adding 1 and 1', () => {
+  expect(1 + 1, 'Woah this should be 2!').toBe(3);
+});
+```
+
 ## Contributors
 
 <!-- ALL-CONTRIBUTORS-LIST:START - Do not remove or modify this section -->
+<!-- prettier-ignore -->
+| [<img src="https://avatars0.githubusercontent.com/u/5610087?v=4" width="100px;"/><br /><sub><b>Matt Phillips</b></sub>](http://mattphillips.io)<br />[💻](https://github.com/mattphillips/jest-expect-message/commits?author=mattphillips "Code") [📖](https://github.com/mattphillips/jest-expect-message/commits?author=mattphillips "Documentation") [💡](#example-mattphillips "Examples") [🤔](#ideas-mattphillips "Ideas, Planning, & Feedback") [🚇](#infra-mattphillips "Infrastructure (Hosting, Build-Tools, etc)") [⚠️](https://github.com/mattphillips/jest-expect-message/commits?author=mattphillips "Tests") [🔧](#tool-mattphillips "Tools") |
+| :---: |
 <!-- ALL-CONTRIBUTORS-LIST:END -->
 
 ## LICENSE