Reorganize source code in preparation to move into aspnet/AspNetCore

.appveyor.yml

.vscode/settings.json

CONTRIBUTING.md

LICENSE.txt

NuGet.config

build.cmd

build.sh

korebuild-lock.txt

korebuild.json

run.cmd

run.ps1

run.sh

src/templating/.gitignore

src/templating/Directory.Build.props

src/templating/Directory.Build.targets

src/templating/NuGetPackageVerifier.json

src/templating/README.md

src/templating/Templating.sln

src/templating/build/dependencies.props

src/templating/build/repo.props