add regular csproj to netstandard sln so everything can be build at once
add regular csproj to netstandard sln so everything can be build at once

rexm/Handlebars.Net,tsliang/Handlebars.Net,esskar/handlebars-core,tsliang/Handlebars.Net,kendallb/Handlebars.Net,rexm/Handlebars.Net