docs: add app.manifest

https://dev.splunk.com/enterprise/reference/packagingtoolkit/pkgtoolkitappmanifest/

app.manifest

@@ -0,0 +1,60 @@
+{
+  "schemaVersion": "2.0.0",
+  "info": {
+    "title": "malware-filter Add-on",
+    "id": {
+      "group": null,
+      "name": "TA-malware-filter",
+      "version": "0.0.11"
+    },
+    "author": [
+      {
+        "name": "Ming Di Leom",
+        "email": null,
+        "company": null
+      }
+    ],
+    "releaseDate": null,
+    "description": "Update malware-filter lookups. https://gitlab.com/malware-filter",
+    "classification": {
+      "categories": [
+        "Utilities",
+        "Reputation",
+        "Threat Intel"
+      ],
+      "developmentStatus": "Alpha",
+      "intendedAudience": "Security Specialists"
+    },
+    "commonInformationModels": null,
+    "license": {
+      "name": "CC0",
+      "text": "./LICENSE-CC0.md",
+      "uri": "https://gitlab.com/malware-filter/splunk-malware-filter/-/blob/main/LICENSE-CC0.md"
+    },
+    "privacyPolicy": {
+      "name": null,
+      "text": null,
+      "uri": null
+    },
+    "releaseNotes": {
+      "name": "Releases",
+      "text": null,
+      "uri": "https://gitlab.com/malware-filter/splunk-malware-filter/-/releases"
+    }
+  },
+  "dependencies": null,
+  "tasks": null,
+  "inputGroups": null,
+  "incompatibleApps": null,
+  "platformRequirements": {
+    "splunk": {
+      "Enterprise": ">=9.0",
+      "Free": ">=9.0"
+    }
+  },
+  "supportedDeployments": [
+    "_standalone",
+    "_distributed"
+  ],
+  "targetWorkloads": null
+}