New edition (kodecocodes#159)

* add runspacing

* add runspacing to all chapters

* use theme instead of hardcode style

* update all project files to use theme instead of hardcode style

* update to headline 6

* fix #422

* remove the `k` prefix, effective dart does not recommend this

* Better handle error

* Add error handling

* FPE - Fix leftover k-prefixed consts

* Chapter 14 - Handle error (kodecocodes#154)

* Handle error

* Handle error

* Add collection import

* Chapter 15 - Handle error (kodecocodes#156)

* Handle error

* FPE - Add moor specific version

Co-authored-by: Cesare Rocchi <[email protected]>

* Errata init (kodecocodes#160)

* chapter 8 starter and final, move super.initState beginning

* chapter 7 init state

* update super.initState chapter 6

* update chapter 5 challenge init state

Co-authored-by: Vincent Ngo <[email protected]>
Co-authored-by: Michael Katz <[email protected]>
Co-authored-by: Kevin Moore <[email protected]>

Updating README