3.8.5.1 Content Pipeline: Add Framework & Lib Changes on Upgrade Guide #304

I partly followed the Upgrading 3.8.x to latest guide for my project and fell into a pitfall with changes to libs:

• Monogame.Framework.DesktopGL cannot provide dependencies mgruntime or libmgruntime.

The guide tells you to upgrade MonoGame.Framework.DesktopGL to 3.8.4.1, but this lib will not provide these dependencies.

There needs to be an entire new section on this guide page for adding a Monogame.Runtime.X package, depending on desired build target, which will provide the missing runtime dependencies.

The change to Monogame.Framework.Native should also be mentioned.

I would also argue maybe this new section should be accompanied by another standalone guide-page which outlines how you are meant to manage complex multi-project .csproj's, including the basics of how .csproj work, what .targets files do, and including getting-going and working under the new build-target project templates here and here.

Ideally users should be able to manually set up a pre-existing project to target multiple different build platforms in a similar pattern to the templates linked above, even if they have not modified .csproj manually before.

I struggled quite a lot figuring all this out via trial and error, and my project still only has one build target. 😔