Update 'README.md'

Added a picture that tells the visitors that this is a mirror.

README.md

@@ -1,3 +1,5 @@
+![Notice, this repository was mirrored to here from Github](https://m1s5.c20.e2-5.dev/files/images/mirror-notice.svg)
+
 # Badí' Date
 
 [![MIT License][license-image]][license-url]