feat(Gitea): Add configuration to enable smtp

https://docs.gitea.io/en-us/install-with-docker/#managing-deployments-with-environment-variables
https://docs.gitea.io/en-us/email-setup/

gitea/docker-compose.smtp.yml

@@ -0,0 +1,12 @@
+version: "3.8"
+
+services:
+  gitea:
+    environment:
+      - GITEA__mailer__ENABLED=true
+      - GITEA__mailer__FROM=${GITEA__mailer__FROM:?GITEA__mailer__FROM not set}
+      - GITEA__mailer__MAILER_TYPE=smtp
+      - GITEA__mailer__HOST=${GITEA__mailer__HOST:?GITEA__mailer__HOST not set}
+      - GITEA__mailer__IS_TLS_ENABLED=true
+      - GITEA__mailer__USER=${GITEA__mailer__USER:?GITEA__mailer__USER not set}
+      - GITEA__mailer__PASSWD="""${GITEA__mailer__PASSWD:?GITEA__mailer__PASSWD not set}"""