UI: added dropdown menus
records: changed text in dedicated box
UI: educate/research collection list update

* updated collection list record boxes (addresses #55)
* introduced “collection areas” col_items / tools
UI: links and routes added to homepage

* prepares the “about” links and pages for content to be added (closes
#65)
* prepares pages for all links in “entry points” (addresses #66)
UI: FIX for tab functionality in collection_list

* FIX for default activated tab on pageload
URL:  `/educate/` -> `/education/`

* name change for the “education” routing (closes #97)
CMS: richer metadata in primary dataset records

* Enriches metadata of CMS Primary Dataset records.
  (addresses #34) (PR #91)

Reviewed-by: Tibor Simko <tibor.simko@cern.ch>