Update README.md

Author: pashagolub

README.md

@@ -1,5 +1,53 @@
-# pg_timetable_gui
-GUI for pg_timetablew
+# pg_timetable_gui: IDE for [pg_timetable](https://github.com/cybertec-postgresql/pg_timetable) scheduler
 
-###
-In the application used open-source [RemixIcons](https://remixicon.com/) set
+**pg_timetable_gui** is a free cross-platform tool for developers and administrators, who need to work with advanced PostgreSQL [pg_timetable](https://github.com/cybertec-postgresql/pg_timetable) scheduler. While every operation can be done in a preferred PostgreSQL client (e.g. psql, pgadmin, dbeaber) we found that special tool may increase productivity during creating, debugging and monitoring jobs.
+
+![pg_timetable_gui main window](res/pg_timetable_gui.png)
+
+Enhanced description of chain and task properties can be found in the official [pg_timetable manual](https://pg-timetable.readthedocs.io/en/master/).
+
+## Controls
+![connect/disconnect](res/shut-down-24px.png) - connect/disconnect to the target PostgreSQL database
+
+![add](res/nav-add-24px.png) - add chain/task
+
+![delete](res/nav-delete-24px.png) - delete chain/task
+
+![edit](res/nav-edit-24px.png) - edit current chain/task
+
+![post](res/nav-post-24px.png) - post chain/task changes to the database
+
+![cancel](res/nav-cancel-24px.png) - cancel editing chain/task
+
+![refresh](res/nav-refresh-24px.png) - refresh chain/task list
+
+![up](res/nav-up-24px.png) - move task up in the chain order
+
+![down](res/nav-down-24px.png) - move task down in the chain order
+
+## Main features
+- List database chains and tasks ✅
+- Add/update/delete chains and tasks ✅
+- Change task order within the chain ✅
+- Execute arbitrary SQL script from file
+- Enhanced *cron-syntax* editor
+- Enhanced task editor with debugging functionality
+
+## Contributing
+
+If you want to contribute to **pg_timetable_gui** and help make it better:
+- ⭐[give a star][star] to the project,
+- feel free to open an 🤚[issue][issue] or even
+- consider submitting a 📜[pull request][PR].
+
+[issue]: https://github.com/cybertec-postgresql/pg_timetable_gui/issues
+[PR]: https://github.com/cybertec-postgresql/pg_timetable_gui/pulls
+[star]: https://github.com/cybertec-postgresql/pg_timetable_gui/stargazers
+
+## Support
+
+For professional support, please contact [Cybertec](https://www.cybertec-postgresql.com/).
+
+## Credits
+- Author: [Pavlo Golub](https://github.com/pashagolub)
+- Media: open-source [RemixIcons](https://remixicon.com/) set