What's Changed
* update publish_to_pypi.yml workflow by michaelchin in https://github.com/GPlates/gplately/pull/146
* add PTT subcommands by michaelchin in https://github.com/GPlates/gplately/pull/148
* 153 add a new "create vgp features from gpmdb" command by michaelchin in https://github.com/GPlates/gplately/pull/155
* 152 add a new markdown page or doc page to document gplately command lines by michaelchin in https://github.com/GPlates/gplately/pull/156
* 154 test for 20 release by michaelchin in https://github.com/GPlates/gplately/pull/157
* 154 test for 20 release by michaelchin in https://github.com/GPlates/gplately/pull/158
**Full Changelog**: https://github.com/GPlates/gplately/compare/v1.2.6...v1.3.0