Dependency resolution docs should be explicit floating versions and pre-release packages

[smarts]

https://docs.nuget.org/ndocs/consume-packages/dependency-resolution#dependency-resolution-in-nuget-3-x
I don't see anything there that talks about pre-release packages in the context of floating versions, and I believe the documentation should be explicit about that. (I apologize if I've missed something)
Based on the rest of the documentation, if I have version 1.9.0 and 1.10.0-beta is available, NuGet 3.x will get the pre-release version. Whether this is true or not, I think it'd be good to update the documentation to be explicit about what happens. If this is true, then I think there should be a way to float versions without getting a pre-release version.

[smarts]

Would you mind providing an explanation in lieu of the updated docs for now? That way I can decide whether I want another issue for a feature request or not.

[danielgreen]

Having tested PackageReference in VS 2017, I found that 1.* would take the latest non-prerelease version.

So if the available packages are 1.5 and 1.6-beta, it will take 1.5.

I'd be interested to learn if other developers are seeing the same behaviour, and what the NuGet team think about including prerelease packages in that floating version (or whether a slightly different floating version could be supported, to indicate that prerelease packages should be included).

[spotlesscoder]

@danielgreen: Yes, this is the default behaviour but I want to be able to include prerelease versions, too

[karann-msft]

Added documentation around that - https://docs.microsoft.com/en-us/nuget/reference/package-versioning#version-ranges-and-wildcards

Pre-release versions are not included when resolving version ranges. Pre-release versions are included when using a wildcard (). The version range [1.0,2.0], for example, does not include 2.0-beta, but the wildcard notation 2.0- does. See issue 912 for further discussion on pre-release wildcards.