Add: Console api doc

doc/Tool_Api.md

@@ -1,7 +1,21 @@
 # Tool Api
 
+Each default tool provided by eruda can be accessed by `eruda.get('Tool Name')`.
+
 ## Console
 
+Displays console logs. Implementation detail follows the [console api spec](https://github.com/DeveloperToolsWG/console-object/blob/master/api.md).
+
+### log, error, info, warn, dir, time/timeEnd, clear, count, assert, table
+
+All these methods can be used in the same way as window.console object.
+
+```javascript
+var console = eruda.get('console');
+console.log('eruda is a console for %s.', 'mobile browsers');
+console.table([{test: 1}, {test: 2, test2: 3}], 'test');
+```
+
 ## Elements
 
 ## Network
@@ -16,4 +30,4 @@
 
 ## Features
 
-## Settings
+## Settings