Config for container network (#96)

Fix #66

Reviewed-on: https://gitea.com/gitea/act_runner/pulls/96
Reviewed-by: Lunny Xiao <[email protected]>

config/config.example.yaml

@@ -36,3 +36,7 @@ cache:
   # The port of the cache server.
   # 0 means to use a random available port.
   port: 0
+
+container:
+  # Which network to use for the job containers.
+  network: bridge