doc: Update document.

Author: jaywcjlove

core/README.md

@@ -39,7 +39,9 @@ const value = [
   { date: '2016/01/11', count: 2 },
   { date: '2016/01/12', count: 20 },
   { date: '2016/01/13', count: 10 },
-  ...[...Array(17)].map((_, idx) => ({ date: `2016/02/${idx + 10}`, count: idx, content: '' })),
+  ...[...Array(17)].map((_, idx) => ({
+    date: `2016/02/${idx + 10}`, count: idx, content: ''
+  })),
   { date: '2016/04/11', count: 2 },
   { date: '2016/05/01', count: 5 },
   { date: '2016/05/02', count: 5 },
@@ -154,7 +156,14 @@ const Demo = () => {
   const [range, setRange] = useState(5)
   return (
     <div>
-      <input type="range" min="0" max="5" step="0.1" value={range} onChange={(e) => setRange(e.target.value)} /> {range}
+      <input
+        type="range"
+        min="0"
+        max="5"
+        step="0.1"
+        value={range}
+        onChange={(e) => setRange(e.target.value)}
+      /> {range}
       <HeatMap
         value={value}
         width={600}