chore(notifications): update README for dynamic plugins

plugins/notifications-backend/README.md

@@ -4,6 +4,16 @@ This Backstage backend plugin provides REST API endpoint for the notifications.
 
 It's backed by a relational database, so far tested with PostgreSQL.
 
+## Deploying as a dynamic plugin
+
+The notifications backend plugin can be loaded either as a static or dynamic plugin.
+
+The steps updating Backstage bellow describe adding it as a static plugin.
+
+To install it as a dynamic plugin, please follow instructions here: https://github.com/janus-idp/backstage-showcase/blob/main/showcase-docs/dynamic-plugins.md#installing-a-dynamic-plugin-package-in-the-showcase
+
+The sections about database, authorization and Catalog are relevant for both cases.
+
 ## Getting started
 
 The plugin uses a relational database to persist messages, it has been tested with the SQLite and PostgreSQL.

plugins/notifications/README.md

@@ -13,6 +13,13 @@ This Backstage front-end plugin provides:
 
 Have `@janus-idp/plugin-notifications-backend` installed and running.
 
+### Installing as a dynamic plugin?
+
+The sections below are relevant for static plugins. If the plugin is expected to be installed as a dynamic one:
+
+- follow https://github.com/janus-idp/backstage-showcase/blob/main/showcase-docs/dynamic-plugins.md#installing-a-dynamic-plugin-package-in-the-showcase
+- add content of `app-config.janus-idp.yaml` into `app-config.local.yaml`.
+
 ### Add NPM dependency
 
 ```