Add Firebase Crashlytics

Fix missing lessons due to relaxed property in skrapeit

Add indicator to current lesson.

* Bump to version 2.1.0

* Add Github Action to create release with APKs

* Bump to version 2.1.0

* Add Github Action to create release with APKs

fix notification and changing language when webview is visible

fix PostEntity in release variant

fix PostEntity in release variant

* add dark theme for swipeRefreshLayout

* add changing toolbar title

* fix