Add history entry for #106

Author: oschwald

HISTORY.rst

@@ -9,6 +9,8 @@ History
 * IMPORTANT: Python 3.7 or greater is required. If you are using an older
   version, please use an earlier release.
 * ``distutils`` is no longer used for building the C extension.
+* Missing ``Py_INCREF`` was added to module initialization for the C
+  extension. Pull request by R. Christian McDonald. GitHub #106.
 
 2.2.0 (2021-09-24)
 ++++++++++++++++++