Add eslint and formatter (#55)
* Add eslint with config and some code adjustments and dep sync
* Add tsfmt incl. adjustments
* Add linter and format-check to github action and readme
* Check format at beginning of github actions
* try to exclude *.d.ts for formatter
* small adjustments
* fix
* use prettier as formatter and remove tsformat
* add prettier-plugin-organize-imports
* address review comments
* Revert "use prettier as formatter and remove tsformat"
This reverts commit 22c79d98
* packages update
