Add initial Keycloak setup with custom theme and Docker configuration

- Created .env.example for environment variable configuration.
- Added .gitignore to exclude .env files.
- Introduced docker-compose files for Keycloak and Postgres services.
- Implemented custom Keycloak theme 'drill-luxe' with associated templates and styles.
- Updated README with deployment instructions and repository details.

keycloak/themes/drill-luxe/login/theme.properties

@@ -0,0 +1,4 @@
+parent=base
+import=common/keycloak
+styles=css/drill-luxe.css
+locales=ru,en