timestamp field needs more details

[jwrosewell]

The timestamp field is shown in the source type.

There is not enough information contained in the value description to understand what the value means.

I propose amending the document to explain that it is the number of minutes that have elapsed since 1st January 2020 stored as an unsigned 32 bit integer.

If the value is seconds then an unsigned 32 bit integer will stop working in approximately 50 years time. It is for this reason I prefer minutes.

Keeping the timestamps across the system to 32 bit unsigned integers also will help reduce data size when byte packing data.