Add Beszel blueprint with Docker Compose and configuration files

- Introduced Docker Compose setup for Beszel service, including port and volume configuration.
- Added logo for Beszel.
- Created template.toml for Beszel with default variables for configuration.

blueprints/beszel/template.toml

@@ -0,0 +1,8 @@
+[variables]
+main_domain = "${domain}"
+
+[config]
+[[config.domains]]
+serviceName = "beszel"
+port = 8090
+host = "${main_domain}"