feat: initial app template catalog with 16 apps

Populate the appstore-apptemplates repo with catalog.json and
per-app config files for all 16 curated Docker apps, each at v1.0.0.

apps/plausible/versions/1.0.0/config.json

@@ -0,0 +1,7 @@
+{
+  "image": "plausible/analytics:latest",
+  "port": 8000,
+  "platformRequirements": {
+    "clickhouse": true
+  }
+}