#81 fix index corruption (#82)

* #81 fix index corruption

#67 Add `is_*type*` functions (#78)

Update version

#69 Fix the `sum` and `avg` function for the only numeric value. (#70)

#67 `length` returns the size of array or length of the string. Add `… (

#68)

* #67 `length` returns the size of array or length of the string. Add `size` function to provide the count of internal elements of arrays and objects.

Fix error handling in cmd (#66)

Add multiline support (#64)

* Fix assignment of key

* Add functions `last`, `first`, `parent`, `root`, and `key`

* Add multiline support for CLI

Fix release version

Update release version

Fixed operation parser (#46)