Updated docker-compose format to version 2

[nilo85]

Updated to v2 format.

I do this because I want to spawn PanteraS inside a custom docker network, and this is first supported in v2.

I cant implement this feature directly here, I will need to patch this file in my use-case for now, might come with a later P/R when i can streamline this aproach

Please do diff without whitespace and it looks cleaner:

index da63045..87b6043 100644
--- a/docker-compose.yml.tpl
+++ b/docker-compose.yml.tpl
@@ -1,6 +1,8 @@
+version: '2'
+services:
   panteras:
     image:          ${PANTERAS_DOCKER_IMAGE}
-  net:        host
+    network_mode:   host
     privileged:     true
     pid:            host
     restart:        "${PANTERAS_RESTART}"```

[nilo85]

Closing this PR, its a bit immature and ads no value at this point

[RiRa12621]

Pleas feel free to create a [ Feature Request ] issue as this might be a valuable feature and should not be forgotten.