Update README.md

add apk object

Author: karenyousefi

README.md

@@ -115,6 +115,7 @@ for a specific attribute. An optional **to_ids** boolean field to disable the ID
 - [objects/annotation](https://github.com/MISP/misp-objects/blob/main/objects/annotation/definition.json) - An annotation object allowing analysts to add annotations, comments, executive summary to a MISP event, objects or attributes.
 - [objects/anonymisation](https://github.com/MISP/misp-objects/blob/main/objects/anonymisation/definition.json) - Anonymisation object describing an anonymisation technique used to encode MISP attribute values. Reference: https://www.caida.org/tools/taxonomy/anonymization.xml.
 - [objects/apivoid-email-verification](https://github.com/MISP/misp-objects/blob/main/objects/apivoid-email-verification/definition.json) - Apivoid email verification API result. Reference: https://www.apivoid.com/api/email-verify/.
+- [objects/apk](https://github.com/MISP/misp-objects/blob/main/objects/apk/definition.json) - Apk object describing a file with meta-information.
 - [objects/artifact](https://github.com/MISP/misp-objects/blob/main/objects/artifact/definition.json) - The Artifact object permits capturing an array of bytes (8-bits), as a base64-encoded string, or linking to a file-like payload. From STIX 2.1 (6.1).
 - [objects/asn](https://github.com/MISP/misp-objects/blob/main/objects/asn/definition.json) - Autonomous system object describing an autonomous system which can include one or more network operators managing an entity (e.g. ISP) along with their routing policy, routing prefixes or alike.
 - [objects/attack-pattern](https://github.com/MISP/misp-objects/blob/main/objects/attack-pattern/definition.json) - Attack pattern describing a common attack pattern enumeration and classification.