Added screenshots to readme file

README.md

@@ -3,4 +3,14 @@
 This application uses Outline Server Management API to manage Outline servers. You can find more
 information on https://getoutline.org.
 
+<picture>
+  <source width="300" media="(prefers-color-scheme: dark)" srcset="app/src/main/play/listings/en-US/graphics/phone-screenshots/1.jpg">
+  <img width="300" src="app/src/main/play/listings/en-US/graphics/phone-screenshots/5.jpg">
+</picture>
+
+<picture>
+  <source width="300" media="(prefers-color-scheme: dark)" srcset="app/src/main/play/listings/en-US/graphics/phone-screenshots/2.jpg">
+  <img width="300" src="app/src/main/play/listings/en-US/graphics/phone-screenshots/6.jpg">
+</picture>
+
 <a href='https://play.google.com/store/apps/details?id=org.sirekanyan.outline'><img height='100' alt='Get it on Google Play' src='https://play.google.com/intl/en_us/badges/images/generic/en_badge_web_generic.png'/></a>