Set default ACME_DIRECTORY for Docker installs to somewhere in a volume

With the previous default, ACME certificates and accounts would be lost upon restarting the container because only the /data folder is bound to a (writable) volume in the suggested docker-compose.yml from the docs.

Author: Sainan

docker/root/etc/templates/app.ini

@@ -20,6 +20,7 @@ DISABLE_SSH      = $DISABLE_SSH
 SSH_PORT         = $SSH_PORT
 SSH_LISTEN_PORT  = $SSH_LISTEN_PORT
 LFS_START_SERVER = $LFS_START_SERVER
+ACME_DIRECTORY   = /data/gitea/acme
 
 [database]
 PATH = /data/gitea/gitea.db

docker/rootless/etc/templates/app.ini

@@ -23,6 +23,7 @@ SSH_PORT         = $SSH_PORT
 SSH_LISTEN_PORT  = $SSH_LISTEN_PORT
 BUILTIN_SSH_SERVER_USER = $RUN_USER
 LFS_START_SERVER = $LFS_START_SERVER
+ACME_DIRECTORY   = /data/gitea/acme
 
 [database]
 PATH = $GITEA_WORK_DIR/data/gitea.db