Merge pull request #1327 from kauemurakami/percent-size

feat:  extensions methods convert value in percent value

+import '../get_main.dart';
+
+//Converts a double value to a percentage
+extension PercentSized on double {
+  // height: 50.0.hp = 50%
+  double get hp => (Get.height * (this / 100));
+  // width: 30.0.hp = 30%
+  double get wp => (Get.width * (this / 100));
+}