Updated BTF specification to version 2.2.1
diff --git a/websites/www.eclipse.org-app4mc-hugo/site/content/documentation/index.md b/websites/www.eclipse.org-app4mc-hugo/site/content/documentation/index.md
index 220104c..1d7da8e 100644
--- a/websites/www.eclipse.org-app4mc-hugo/site/content/documentation/index.md
+++ b/websites/www.eclipse.org-app4mc-hugo/site/content/documentation/index.md
@@ -40,7 +40,7 @@
 ---
 
 #### BTF Specification
-Current version: [V2.2.0 (2020-03-01)](https://archive.eclipse.org/app4mc/documents/misc/BTF_Specification_2.2.0.pdf)
+Current version: [V2.2.1 (2021-01-07)](https://archive.eclipse.org/app4mc/documents/misc/BTF_Specification_2.2.1.pdf)
 
 Previous versions:
 [V2.1.5 (2016-01-29)](https://archive.eclipse.org/app4mc/documents/misc/BTF_Specification_2.1.5.pdf)