Add static ASP.NET/Angular/Node.js site

[jnickg]

Overview

Resolves #6. Resolves #7.

This PR, along with some configuration on Heroku, allow us to automatically deploy to https://dungen-core.herokuapp.com/ each time we push a commit to master. Hopefully we never have to futz with this stuff often (if ever), and we can just focus on adding new pages and viewmodels, and new API functionality.

It would be good to add another Heroku dyno that deployed for every pull request or something, or allowed manual deploys for testing, so we could test changes before merging PRs. I'll look into that.

Commit Messages

• Resolves #6. Resolves #7
• Also update documentation for new tool(s) needed to build/debug
• Top-level heroku.yml file is used to construct container using dungen/Dockerfile, which runs the same setup as the dungen/dungen-site/dungen-site.csproj build steps, translated for Heroku
• Update dungen/dungen-site/dungen-site.csproj s/t the npm commands are only run if we're building on Windows (may become a bad assumption later)
• Add Dockerfile and a bunch of other files to the VS solution
• Add curl to docker image as this is needed by Heroku for better logging
• Fix known AspNet Core NuGet bug
  • Heroku server was hitting this on deploy
  • See this issue for more details
• Update all NuGet packages to latest
• Change program.cs to use the Heroku-provided port, and update local debug settings to pass in PORT in the same way