[WIP] Remove knife bootstrap windows

[kvivek1115]

Description

• In order to remove bootstrapping support from knife-windows related code has been refactored.
• Updated the README doc.

Related PR

https://github.com/chef/knife-windows/pull/477

Check List

• [ ] New functionality includes tests
• [x] All tests pass
• [x] All commits have been signed-off for the Developer Certificate of Origin. See https://github.com/chef/chef/blob/master/CONTRIBUTING.md#developer-certification-of-origin-dco
• [x] PR title is a worthy inclusion in the CHANGELOG

[btm]

we should probably keep knife windows bootstrap winrm and knife windows bootstrap ssh commands, but have them warn you to use knife bootstrap ... instead and then exit. that way it is immediately obvious the new command to type without searching the internet or looking at the docs.

[kvivek1115]

@btm restore the knife windows bootstrap winrm and knife windows bootstrap ssh commands. And added the following fatal warning

FATAL: *knife windows bootstrap winrm*
 Core Chef now supports bootstrapping Windows systems without a knife plugin

 Use 'knife bootstrap -o winrm' instead.

 For more detail https://github.com/chef/chef/blob/master/RELEASE_NOTES.md#knife-bootstrap

Thanks

[kvivek1115]

@btm Should I created separate PR for README doc updates As I missed it?