docs(operators): add documentation for take

src/operator-docs/filtering/take.ts

@@ -1,6 +1,57 @@
 import { OperatorDoc } from '../operator.model';
 
 export const take: OperatorDoc = {
-  'name': 'take',
-  'operatorType': 'filtering'
+  name: 'take',
+  operatorType: 'filtering',
+  signature: 'public take(count: number): Observable<T>',
+  useInteractiveMarbles: true,
+  parameters: [
+    {
+      name: 'count',
+      type: 'number',
+      attribute: '',
+      description: 'The maximum number of next values to emit.'
+    }
+  ],
+  marbleUrl: 'http://reactivex.io/rxjs/img/take.png',
+  shortDescription: {
+    description: `Emits only the first count values emitted by the source Observable.`,
+    extras: [
+      {
+        type: 'Tip',
+        text: `Takes the first count values from the source, then completes.`
+      }
+    ]
+  },
+  walkthrough: {
+    description: `<p>
+      <span class="markdown-code">take</span> returns an Observable that emits only the first count values emitted by the source Observable.
+    </p>
+    <p>
+      If the source emits fewer than count values then all of its values are emitted.
+      After that, it completes, regardless if the source completes.
+    </p>`
+  },
+  examples: [
+    {
+      name:
+        'Take the first 5 seconds of an infinite 1-second interval Observable',
+      code: `
+      const interval = Rx.Observable.interval(1000);
+      const five = interval.take(5);
+      five.subscribe(x => console.log(x));
+      // Logs below values
+      // 0
+      // 1
+      // 2
+      // 3
+      // 4
+      `,
+      externalLink: {
+        platform: 'JSBin',
+        url: 'http://jsbin.com/yujema/embed?html,js,console'
+      }
+    }
+  ],
+  relatedOperators: ['takeLast', 'takeUntil', 'takeWhile', 'skip']
 };