add missing 2.1.1 changelog
+2020-08-18 2.1.1:
+--------------------
+ * bugfixes:
+ - #10172 [component: bokehjs] [BUG] Can't resolve 'styles/annotations.css' when importing BokehJS
+ - #10175 [component: server] [BUG] Serve application at random port failed
+ - #10181 [BUG] Unable to set `LabelSet.text_align` with `bokeh serve`
+ - #10197 [BUG] Can't select bar_line_color in ColorBar
+ - #10204 [component: bokehjs] return typed arrays as lists
+ * tasks:
+ - #10212 [component: docs] Release notes for 2.1.1
+
2020-06-14 2.1.0:
--------------------
* bugfixes:
2013-09-03 0.1:
--------------------
* initial release
+
