Update Changelog.md.

Author: shorowit

Changelog.md

@@ -33,6 +33,7 @@ __Bugfixes__
 - Fixes zero energy use for a ventilation fan w/ non-zero fan power and zero airflow rate.
 - Fixes excessive heat transfer when foundation wall interior insulation does not start from the top of the wall.
 - Fixes how relative paths are treated when using an OpenStudio Workflow.
+- Fixes possible simulation error if a slab has an ExposedPerimeter near zero.
 - BuildResidentialHPXML measure:
   - Fixes aspect ratio convention for single-family attached and multifamily dwelling units.