Correct spelling

Signed-off-by: Valdnet <47037905+Valdnet@users.noreply.github.com>

README.md

@@ -1,7 +1,7 @@
 # End-to-End Encryption App
 
-This app provides all the necessary APIs to implement end-to-end encryption
-on the client side. Additionally it makes sure that end-to-end encrypted
+This app provides all the necessary APIs to implement End-to-End encryption
+on the client side. Additionally it makes sure that End-to-End encrypted
 files are not accessible with the web interface and other WebDAV clients.
 
 Here you can find the [API documentation](https://github.com/nextcloud/end_to_end_encryption/blob/master/doc/api.md).