Complete DESCRIPTION file

• Title (with a capital letter in each word)
• Date: to update
• Depends, Imports, Suggests
• Description (do not start with "This package" or the package name)
• BugReports: issues from the repository
• Vignette
• URL: link of the deposit on forgemia (or create web page using pkgdown, version it (add it in gitignore) and add the url)
• LazyData: if data are include in the package