Getting started feedback

[parched]

Firstly, thanks for creating this @jamescourtney, it looks great.

I just want to share some things I stumbled on when first trying this. I think some minor tweaks to the readme might help, which I'm happy to submit a PR if you don't want to do it yourself.

The steps in the "Getting Started" section implied to me they were all I needed to do. However, it was only after I dug around the samples a bit that I figured it out.

1. The changes need to the .csproj file. Specifically, FlatSharpSchema is what I was missing. I think the PackageReferences are fairly obvious but it wouldn't hurt to include them.
2. It took me a while to figure out that the Serialize method I needed was an extension method, and there hadn't been some API change to the non-extension method with 3 args between the readme and the current release. Just adding using FlatSharp; to the example should suffice.

My colleague also tried the library and stumbled on the same issues too.

I also hit this but I don't think that needs to be mentioned in the readme.