ENG-2595 (#3976)

* feat: implement railway secret sync

* fix: railway sync config

* feat: add documentation on railway

* fix: undo mock on-prem change

* lint: fix

* fix: cleanup railway integration

* fix: retry and doc images

* fix: sync fields

* fix: query typo

* Update docs/docs.json

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

frontend/src/hooks/api/appConnections/enums.ts

@@ -29,5 +29,6 @@ export enum AppConnection {
   Gitlab = "gitlab",
   Cloudflare = "cloudflare",
   Bitbucket = "bitbucket",
-  Zabbix = "zabbix"
+  Zabbix = "zabbix",
+  Railway = "railway"
 }