Updated Installation Examples (markdown)

Installation-Examples.md

@@ -20,7 +20,7 @@ We are going to use this docker based mailserver:
 
   services:
     mail:
-      image: tvial/docker-mailserver:latest
+      image: docker.io/mailserver/docker-mailserver:latest
       hostname: mail
       domainname: example.org
       container_name: mail
@@ -73,7 +73,7 @@ We are going to use this docker based mailserver:
 
 - Pull the docker image:
   ```
-  docker pull tvial/docker-mailserver:latest
+  docker pull docker.io/mailserver/docker-mailserver:latest
   ```
 
 - Now generate the DKIM keys with `./setup.sh config dkim` and copy
@@ -208,7 +208,7 @@ Truncated list of neccessary labels on the mailserver container:
 version: '2'
 services:
   mail:
-    image: tvial/docker-mailserver:release-v7.2.0
+    image: docker.io/mailserver/docker-mailserver:release-v7.2.0
     restart: always
     networks:
       - proxy