Change Cake.Core Dependency to 2.0.0+

[ericburcham]

Description

During my usage of this Cake plugin, I noticed the following warning message:
The assembly 'Cake.DocFx, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'
is referencing an older version of Cake.Core (1.0.0).
For best compatibility it should target Cake.Core version 2.0.0.

I decided to see if I couldn't fork your repo and add support for Cake.Sure 2.0.0.

I was able to update the dependencies, and the projects compile fine in Visual Studio. But the Cake Build recipe is now broken. I had to update the solution projects to net5.0 in order to adopt Cake.Core 2+, and it looks like the Cake dependencies in the plugin's build script only support netcoreapp. I do not have time to take the work further without instruction, but if you can provide guidance to solve those problems, I'll spend some more time and see what I can do.

Related Issue

Latest Cake Build emits warning: The assembly 'Cake.DocFx, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' is referencing an older version of Cake.Core (1.0.0). For best compatibility it should target Cake.Core version 2.0.0.

Motivation and Context

I'm mostly trying to be helpful.

How Has This Been Tested?

See the description.

Types of changes

• [x ] Breaking change - If following semantic versions, this would require a new major version, as the TargetFramework had to be updated.

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly. - I'm happy to do so with some guidance.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.