(#46) Set pubspec.yaml description to match minSdkVersion

Author: Laks Castro

pubspec.yaml

@@ -1,5 +1,5 @@
 name: shared_storage
-description: "Flutter plugin to get Android shared folders like DCIM, Downloads, Video, Audio. Works with Android 4.1 (API Level 16+)"
+description: "Flutter plugin to get Android shared folders like DCIM, Downloads, Video, Audio. Works with Android 4.4 (API Level 19+)"
 version: 0.4.0
 homepage: https://github.com/lakscastro/shared-storage
 repository: https://github.com/lakscastro/shared-storage