Add gradle commands

pages/common/gradle.md

@@ -0,0 +1,15 @@
+# Gradle
+
+> Gradle is the official build system for Android Studio
+
+- Compile a package
+
+`gradle build`
+
+- Clear the build folder
+
+`gradle clean`
+
+- Compile and Release package
+
+`gradle assembleRelease`