Add smbios information to system information guide

[briangreenery]

There are a lot of examples at: https://bigfix.me/analysis/details/2994751

We should include these in the guide, and should see what can be included in the smbios reference.

[jgstew]

Sorry I never got back to this.

I definitely want to contribute to developer.bigifix.com, particularly when it comes to things I'd be writing anyway.

It is a little confusing knowing where to put what and why within the current structure of developer.bigfix.com and I haven't spent the time to get over that.

[briangreenery]

I'll add information about what is defined where in the readme. The relevance reference is a little special in that the documentation for a relevance property can be copied to many different places.

[jgstew]

The guide for SMBIOS would go here: https://github.com/bigfix/developer.bigfix.com/tree/master/site/pages/relevance/guide/client