Organize dependencies in README.

Author: diogobernardino

README.md

@@ -13,7 +13,10 @@ Note: WilliamChart v3 has been completely re-written from scratch in Kotlin and
 ### Gradle 
 
 ``` groovy
+// Charts
 implementation 'com.diogobernardino:williamchart:3.7.1'
+
+// Tooltips
 implementation 'com.diogobernardino.williamchart:tooltip-slider:3.7.1'
 implementation 'com.diogobernardino.williamchart:tooltip-points:3.7.1'
 ```