Add README files for various applications: Decidim, Discourse, Example Admin, Example App, Ghost, Immich, Keila, Lemmy, Listmonk, Loomio, Matrix, Memcached, MySQL, Open WebUI, OpenProject, PostgreSQL, Redis, and vLLM

postgres/README.md

@@ -1 +1,19 @@
-# Postgress app
+# PostgreSQL
+
+PostgreSQL is a powerful, open-source relational database system. This deploys a shared PostgreSQL instance used by many Wild Cloud apps.
+
+## Dependencies
+
+None. PostgreSQL is a standalone infrastructure service.
+
+## Configuration
+
+Key settings configured through your instance's `config.yaml`:
+
+- **storage** - Persistent volume size (default: `20Gi`)
+- **port** - Service port (default: `5432`)
+- **timezone** - Server timezone (default: `UTC`)
+
+## Usage
+
+Apps that depend on PostgreSQL (such as Immich, Gitea, Discourse, Mastodon, and others) will connect to it at `postgres.postgres.svc.cluster.local:5432`. Each app creates its own database and user via a db-init job during deployment. Root credentials are managed through the secrets system.