Update CHANGELOG

Signed-off-by: Adrian 'nex' Schollmeyer <adrian.schollmeyer@fem.tu-ilmenau.de>

CHANGELOG.md

@@ -8,3 +8,4 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   * Add first Icinga2 Host object generators
     * Script `generate-icinga-generic-host.py`
     * Script `generate-icinga-switch-host.py`
+  * Add Jinja2 config templates