Update README.md

README.md

@@ -51,3 +51,4 @@ A collection of essential resources related cyber threat intelligence theory
 | [Recorded Future](https://recordedfuture.com)| Recorded Future periodically updates a handbook detailing their vendor-biased roadmap for building an intelligence-led security program. This is useful for understanding what threat intelligence capabilities may need to be integrated with an enterprise CTI program | [The Intelligence Handbook: Fourth Edition](https://go.recordedfuture.com/hubfs/ebooks/intelligence-handbook-fourth-edition.pdf) |
 | [Recorded Future](https://recordedfuture.com)| Recorded Future maintains a handbook detailing their vendor-biased playbooks for responding to typical CTI-type detections within an enterprise CTI program. This is useful for understanding what threat intelligence response cases may look like in an enterprise CTI program | [The Intelligence Playbook: Practical Applications Across the Enterprise](https://go.recordedfuture.com/hubfs/The_Intelligence_Playbook_Practical_Applications_Across_the_Enterprise.pdf) |
 | [CREST](https://www.crest-approved.org/)| CREST released their CTI Maturity Model Assessment Tool (MMAT) in 2020, a customizable and modular tool for assessing the maturity of a threat intelligence program for free. This tool has three types: Summary, Intermediate, Detailed. In 2022, the tool vanished from CREST's website, but is archived by Curated Intelligence  | [CREST CTI Maturity Model Assessment Tool (MMAT)](https://github.com/curated-intel/CTI-fundamentals/tree/main/Archive/CREST%20CTI%20Maturity%20Model%20Tool) |
+| [Mandiant](https://www.mandiant.com/) | The core skills framework provides guidance with three things: 1. determine appropriate development roadmaps to ensure CTI skills progression; 2. provide a guidepost for aspirant CTI analysts to tailor their studies; 3. assist network defenders in understanding the roles and responsibilities of a CTI analyst | [The Mandiant Cyber Threat Intelligence (CTI) Analyst Core Competencies Framework](https://www.mandiant.com/sites/default/files/2022-05/cti-analyst-core-competencies-framework-v1.pdf) |