Separate environment configs (#6597)

* Separate environment configs

* wip

* wip

* test

* plugins

* test

* test

* .sequelizerc, unfortunately can't go through /utils/environment due to not supporting TS

* docker-compose -> docker compose

* fix: .local wipes .development

* Add custom validation message for invalid SECRET_KEY (often confused)

plugins/iframely/plugin.json

@@ -1,5 +1,5 @@
 {
   "name": "Iframely",
   "description": "Integrate Iframely to enable unfurling of arbitrary urls",
-  "requiredEnvVars": ["IFRAMELY_URL", "IFRAMELY_API_KEY"]
+  "requiredEnvVars": ["IFRAMELY_API_KEY"]
 }