Add directions for using the github version of the package (#166)

Author: baronfel

DEVGUIDE.md

@@ -15,6 +15,13 @@ Then, you can use `dotnet add package Microsoft.NET.Build.Containers -prerelease
 
 You can also always clone this repository, run `dotnet build`, and use the newly-generated nupkg.
 
+To use the package built from the CI pipeline:
+
+* add the github package source to your nuget.config of choice
+  * `dotnet nuget add source https://nuget.pkg.github.com/dotnet/index.json --name dotnet-org-github --username <your github username> --password <your github PAT with read:packages permission at minimum> --configfile <path to desired nuget config file>`
+* add the package to a project
+  * `dotnet add package Microsoft.NET.Build.Containers --prerelease` (or `--version <version number>`)
+
 To use your locally built packages:
 
 * Add a local nuget source:
@@ -40,4 +47,4 @@ To use your locally built packages:
 
 * [OCI Image Format spec](https://github.com/opencontainers/image-spec/blob/main/spec.md)
 * [Docker Registry API docs](https://docs.docker.com/registry/spec/api/)
-* [Setting up a local Docker registry](https://docs.docker.com/registry/)
+* [Setting up a local Docker registry](https://docs.docker.com/registry/)