docs: Manual Update and docker-compose cleanup (#61)

* Added command to trigger a manual report update. Removes verison-tag from docker-compose, since its deprecated

* chore: Added docker-compose examples and env-file

- Added examples-folder
- Added an example for a docker-compose with mysql
- Added an example for a docker-compose with postgres
- Extracted the most important variables to an env.example file
- Added some documentation on how to use the env-file and the compose files

examples/env.example

@@ -0,0 +1,23 @@
+# mysql root password. Irrelevant if you are using postgres
+ROOT_DB_PASSWORD=
+
+# database password for the dmarc user
+DMARC_DB_PASSWORD=
+
+# the email address receiving the DMARC reports
+DMARC_EMAIL=
+
+# the password for the email address receiving the DMARC reports
+DMARC_PASSWORD=
+
+# the server the email address is hosted on
+IMAP_SERVER=
+
+# optional: default is 993
+IMAP_PORT=
+
+# optional: default is "processed"
+IMAP_MOVE_FOLDER=
+
+# optional: default is "error"
+IMAP_MOVE_FOLDER_ERR=