Update changelog (#51)

Author: juliusgeo

changelog.rst

@@ -2,11 +2,23 @@
 Changelog
 =========
 
+Changes in version 1.2.0
+------------------------
+- Added ability to configure explain command options using constructor
+  keyword parameters ``verbosity`` and ``comment``.
+- Added support for PyMongo 4.0
+- Added support for Python 3.9 and 3.10
+
 Changes in version 1.1.1
 ------------------------
 - ``ExplainCollection`` now importable from top level like so: ``from pymongoexplain import ExplainCollection``
 - Added aliases so that now both ``ExplainCollection`` and ``ExplainableCollection`` are importable
 
+Changes in version 1.1.0
+------------------------
+- Added better commandline argument parsing to the CLI tool
+- Various fixes to the documentation
+
 Changes in version 1.0.0
 ------------------------
 - Initial ``ExplainCollection`` API