Use let instead of var

doc/API.md

@@ -14,7 +14,7 @@ Initialize eruda.
 |useShadowDom=true|boolean     |Use shadow dom for css encapsulation                                                     |
 
 ```javascript
-var el = document.createElement('div');
+let el = document.createElement('div');
 document.body.appendChild(el);
 
 eruda.init({
@@ -60,7 +60,7 @@ eruda.position(); // -> {x: 20, y: 20}
 Get tool, eg. console, elements panels.
 
 ```javascript
-var console = eruda.get('console');
+let console = eruda.get('console');
 console.log('eruda');
 ```
 

doc/README_CN.md

@@ -80,7 +80,7 @@ Js文件对于移动端来说略重（gzip后大概100kb）。建议通过url参
 * tool：指定要初始化哪些面板，默认加载所有。
 
 ```javascript
-var el = document.createElement('div');
+let el = document.createElement('div');
 document.body.appendChild(el);
 
 eruda.init({

doc/TOOL_API.md

@@ -22,7 +22,7 @@ Display console logs. Implementation detail follows the [console api spec](https
 |maxLogNum          |string |Max log number                 |
 
 ```javascript
-var console = eruda.get('console');
+let console = eruda.get('console');
 console.config.set('catchGlobalErr', true);
 ```
 
@@ -33,7 +33,7 @@ All these methods can be used in the same way as window.console object.
 Note: When called, a corresponding event is triggered.
 
 ```javascript
-var console = eruda.get('console');
+let console = eruda.get('console');
 console.log('eruda is a console for %s.', 'mobile browsers');
 console.table([{test: 1}, {test: 2}, {test2: 3}], 'test');
 console.error(new Error('eruda'));
@@ -295,7 +295,7 @@ Add color to select a color.
 Add a separator.
 
 ```javascript
-var cfg = eruda.util.createCfg('test');
+let cfg = eruda.util.createCfg('test');
 
 cfg.set(eruda.util.defaults(cfg.get(), {
     testBool: true,