Start changelog for 3.1.0 release (#99)

* Prepare 3.1.0 release

* Clean parentheses and fix heading display

* Update CHANGELOG.md

CHANGELOG.md

@@ -1,16 +1,23 @@
-## [3.0.1](https://github.com/deshaw/jupyterlab-execute-time/compare/v3.0.0...v3.0.1) (2023-08-02))
+## [3.1.0](https://github.com/deshaw/jupyterlab-execute-time/compare/v3.0.1...v3.1.0) (unreleased)
+
+### Added
+
+- Make display of last execution date optional [#94](https://github.com/deshaw/jupyterlab-execute-time/pull/94)
+- Enable defining custom date format [#93](https://github.com/deshaw/jupyterlab-execute-time/pull/93)
+
+## [3.0.1](https://github.com/deshaw/jupyterlab-execute-time/compare/v3.0.0...v3.0.1) (2023-08-02)
 
 ### Changed
 
 - Ensure this only installs with Jupyterlab@4
 
-~## [3.0.0](https://github.com/deshaw/jupyterlab-execute-time/compare/v2.3.1...v3.0.0) (2023-05-19))~
+## ~[3.0.0](https://github.com/deshaw/jupyterlab-execute-time/compare/v2.3.1...v3.0.0) (2023-05-19)~
 
 ### Changed
 
 - **Breaking**: Ported to JupyterLab 4.x.
 
-## [2.3.1](https://github.com/deshaw/jupyterlab-execute-time/compare/v2.3.0...v2.3.1) (2022-12-28))
+## [2.3.1](https://github.com/deshaw/jupyterlab-execute-time/compare/v2.3.0...v2.3.1) (2022-12-28)
 
 ### Fixed
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "jupyterlab-execute-time",
-  "version": "3.0.1",
+  "version": "3.1.0",
   "description": "Display cell timings in Jupyter Lab",
   "keywords": [
     "jupyter",