Documentation improvements

[jerryd]

On the documentation website. It would be useful to define the input fields for each card. For example the FR card is not obvious what each field is. <aybe I look in the wrong place.

Jerry KF7RCC

[KJ7LNW]

It may be a good idea to link to it in the docs, too. NEC2 is a standard so its centrally defined. I think this is what you're looking for:

• https://www.nec2.org/part_3/toc.html
• https://www.nec2.org/