description of dataset content

[sverhees]

It would be helpful to have a short description of what the user can find in the feature datasets (on the page maps&data under the heading 3 Database), since only a few of the dataset columns are shown on the website.

[agricolamz]

• create an .md file with the dataset discriptions
• put them into data/md_description

path example data/md_description/standard_of_comparison.md