fix(specs): re-add link to latest release

Author: zeitgeist

specs/index.bs

@@ -4,6 +4,7 @@ Shortname: ileap-extension
 Status: LD
 Status Text: Draft Technical Specification
 ED: https://sine-fdn.github.io/ileap-extension/
+TR: https://sine-fdn.github.io/ileap-extension/TR/2024/ileap-extension-20240605/
 Canonical URL: ED
 Editor: Violetta Matzoros, https://www.smartfreightcentre.org, violetta.matzoros@smartfreightcentre.org
 Editor: Gabriela Rubio Domingo, https://www.smartfreightcentre.org, gabriela.rubiodomingo@smartfreightcentre.org