Add descriptions of datasets

[Nowosad]

It should be added to each .R file as @references.

[kadyb]

For example, do you mean "http://www.gugik.gov.pl/pzgik/zamow-dane/ortofotomapa" and other links to the GUGiK website? The biggest disadvantage is that all descriptions are only available in Polish language. The same is for legislation (all acts) and databases.

[Nowosad]

For example, do you mean "http://www.gugik.gov.pl/pzgik/zamow-dane/ortofotomapa" and other links to the GUGiK website?

Yep. You can add "(in Polish) " after the url.

[kadyb]

We talked about creating vignettes for each function, so why not add sections describing the data (definitions, content, parameters) at the beginning of vignettes? It will be helpful for both Polish and foreign users.

[Nowosad]

Also a neat idea.

[kadyb]

1. Orthophotomap
2. Digital Elevation Model
3. Topographic Database