Added first version dotnet core 2.2 template

[csakshaug]

dotnet core 2.2 template

Description

This a is dotnet core 2.2 template based on the csharp template, but it also updated the base docker image location (using new Microsoft registry) and also fixed the that the handler uses dotnet core and not standard.

The csharp template has mixed with net core and standard 2.1. It also has some flaws from a "dotnet developing perspective", I have not addressed this in this pull request.

Motivation and Context

We should have updated templates both for 2.2 and 3.0. The name csharp could be misleading, my suggestion is to start using "netcore" or "netstandard" as basename instead of "csharp".

The reason why I have selected netcore is same as Microsoft using as a prefix for the framework in the csproj file.

• [x] I have raised an issue to propose this change (required)

Which issue(s) this PR fixes

Fixes #176

How Has This Been Tested?

Only testet docker build

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Version change (see: Impact to existing users)

Impact to existing users

None, new naming for dotnet core templates

Checklist:

• [x] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I've read the CONTRIBUTION guide
• [ ] I have signed-off my commits with git commit -s
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.

[derek[bot]]

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