docs: update _coverpage.md

yanglbme · yanglbme · commit 04fc6ca2fcb6 · 2019-03-12T09:08:55.000+08:00
diff --git a/_coverpage.md b/_coverpage.md
@@ -1,4 +1,4 @@
-![logo](images/icon.png)
+[![logo](images/icon.png)](https://github.com/doocs/advanced-java)
 
 # Java 进阶扫盲
 

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-![logo](images/icon.png)`
	`1`	`+[![logo](images/icon.png)](https://github.com/doocs/advanced-java)`
`2`	`2`
`3`	`3`	`# Java 进阶扫盲`
`4`	`4`