Feature: Skeleton Methods Generated as Async Methods (#876)

* Added ReqnrollConfiguration Trace setting 'GenerateStepDefinitionSkeletonAsAsync` (boolean). When true, step definition generated when a step is missing will use the Async form (supporting C#, VB and F#).

* Updated tests to include testing of async step definition templates.

* Update Changelog

* Modified approach to combine the async flag into the StepDefinitionStyle enum.

* small cleanup

* update docs

* remove F# style from docs, as it is anyway not documented in the config part

* UNDO default setting change

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Co-authored-by: Gáspár Nagy <[email protected]>

update CHANGELOG

Fix: nuspec referencing incorrect Cucumber.HtmlFormatter version (#868)

* Fix: nuspec referencing incorrect Cucumber.HtmlFormatter version

* fix CHANGELOG

Updated CHANGELOG to include issue number and contributor handle.

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Co-authored-by: Jorg de Bont <[email protected]>
Co-authored-by: Gáspár Nagy <[email protected]>

fix CHANGELOG

Update CHANGELOG

Remove 'Improvements' section from CHANGELOG

Removed the 'Improvements' section from the changelog.

update CHANGELOG

Add TUnit to CHANGELOG

Update CHANGELOG

bump version to 2.4.0