Add missing release to download version history (#624)

Author: swebb2066

src/site/markdown/download.md.in

@@ -56,6 +56,7 @@ in many unix distributions.
 
 | Version                  | Release Date |
 | :--------------------------: |  :----------------------:   |
+| [1.6.1](${LOG4CXX_DOCUMENTATION_URL}/1.6.1/download.html) | Jan-2026 |
 | [1.5.0](${LOG4CXX_DOCUMENTATION_URL}/1.5.0/download.html) | Aug-2025 |
 | [1.4.0](${LOG4CXX_DOCUMENTATION_URL}/1.4.0/download.html) | Mar-2025 |
 | [1.3.1](${LOG4CXX_DOCUMENTATION_URL}/1.3.1/download.html) | Nov-2024 |