bumping technology readiness level to 8/9

Author: proycon

README.md

@@ -3,7 +3,7 @@
 </p>
 
 [![Project Status: Active – The project has reached a stable, usable state and is being actively developed.](https://www.repostatus.org/badges/latest/active.svg)](https://www.repostatus.org/#active)
-![Technology Readiness Level 7/9 - Release Candidate - Technology ready enough and in initial use by end-users in intended scholarly environments. Further validation in progress.](https://w3id.org/research-technology-readiness-levels/Level7ReleaseCandidate.svg)
+![Technology Readiness Level 8/9 - Complete - Technology complete and qualified, released for all end-users in scholarly environments.](https://w3id.org/research-technology-readiness-levels/Level8Complete.svg)
 
 # STAM: Stand-off Text Annotation Model