Add Script: Joplin Server (#7879)

Co-authored-by: push-app-to-main[bot] <203845782+push-app-to-main[bot]@users.noreply.github.com>
Co-authored-by: Slaviša Arežina <58952836+tremor021@users.noreply.github.com>
Co-authored-by: Tobias <96661824+CrazyWolf13@users.noreply.github.com>

frontend/public/json/joplin-server.json

@@ -0,0 +1,40 @@
+{
+  "name": "Joplin Server",
+  "slug": "joplin-server",
+  "categories": [
+    12
+  ],
+  "date_created": "2025-09-12",
+  "type": "ct",
+  "updateable": true,
+  "privileged": false,
+  "interface_port": 22300,
+  "documentation": "https://joplinapp.org/help/",
+  "config_path": "/opt/joplin-server/.env",
+  "website": "https://joplinapp.org/",
+  "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons/webp/joplin.webp",
+  "description": "Joplin - the privacy-focused note taking app with sync capabilities for Windows, macOS, Linux, Android and iOS.",
+  "install_methods": [
+    {
+      "type": "default",
+      "script": "ct/joplin-server.sh",
+      "resources": {
+        "cpu": 2,
+        "ram": 4096,
+        "hdd": 20,
+        "os": "Debian",
+        "version": "12"
+      }
+    }
+  ],
+  "default_credentials": {
+    "username": "admin@localhost",
+    "password": "admin"
+  },
+  "notes": [
+    {
+      "text": "Application can take some time to build, depending on your host speed. Please be patient.",
+      "type": "info"
+    }
+  ]
+}