Add verify to extension readme

Author: Ismael

extensions/README.md

@@ -74,6 +74,7 @@ The following community-contributed extensions are available in [`catalog.commun
 |-----------|---------|-----|
 | V-Model Extension Pack | Enforces V-Model paired generation of development specs and test specs with full traceability | [spec-kit-v-model](https://github.com/leocamello/spec-kit-v-model) |
 | Cleanup Extension | Post-implementation quality gate that reviews changes, fixes small issues (scout rule), creates tasks for medium issues, and generates analysis for large issues | [spec-kit-cleanup](https://github.com/dsrednicki/spec-kit-cleanup) |
+| Verify Extension | Post-implementation quality gate that validates implemented code against specification artifacts | [spec-kit-verify](https://github.com/ismaelJimenez/spec-kit-verify) |
 
 ## Adding Your Extension