* deps: Add OTP 21.0 Support
  * deps(): pin rustler to 0.18
  * deps(): update deps to newer versions
  * deps(): pin current working dependencies in rustler
  * deps(): update rustler
  * refactor(): update to the newest rustler types
  * choir(): apply rustfmt
  * feat: added list_cf/2
  * docs: update installation documentation to target rox ~> 2.0