Adding a package description for the ELM middleware package
Adding a package description for the ELM middleware package

Fixes: https://github.com/aspnet/Diagnostics/issues/100

aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore