Update README.md

Author: 壳

README.md

@@ -20,8 +20,17 @@
 
 # Usage
 
-Gradle:
+**Step 1.** Add the JitPack repository to your build file
+```
+allprojects {
+	repositories {
+		...
+		maven { url 'https://jitpack.io' }
+	}
+}
+```
 
+**Step 2.** Add the dependency
 ```
 compile 'com.github.ImKarl:WaitView:{latestVersion}'
 ```