Immich: Add Immich installer configuration

Change-Id: I88796e42d0b0b14d84b094d4a1c5213b43c56f2a
diff --git a/charts/immich/templates/checks.yaml b/charts/immich/templates/checks.yaml
new file mode 100644
index 0000000..b67aa67
--- /dev/null
+++ b/charts/immich/templates/checks.yaml
@@ -0,0 +1,7 @@
+{{- $name := .Values.immich.persistence.library.existingClaim | required ".Values.immich.persistence.library.existingClaim is required." -}}
+
+{{ if .Values.postgresql.enabled }}
+  {{ if not .Values.useDeprecatedPostgresChart}}
+    {{ fail "The postgres subchart is deprecated. Please see https://github.com/immich-app/immich-charts/issues/149 for more detail." }}
+  {{ end }}
+{{ end }}