UI: use translated collection names

* (closes #206)
UI: records: file desc + preview only with .ig

* templates: real file descriptions (closes #204)
* Event preview in derived datasets shows only if “.ig” files exist
(closes #164)
templates: CMS Physics Objects link fix

* Fixes links to CMS Physics Objects page.
  (addresses #153) (addresses #198)

* In addition, removes `^L` and `^K` characters in the text.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
templates: one more link to Physics Objects

* Adds one more link to CMS Physics Objects.
  (addresses #153) (addresses #198)

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
base: JSON data model fix for external URLs

* Fixes JSON data model for external URLs (`8564`).

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
UI: "disclaimer" text changed

* (closes #139)
CMS: author/experiment field update in Tools

* Fixes author fields and accelerator/experiment field in
  `cms-tools-ispy.xml`.  (closes #142) (addresses #145) (PR #217)

Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
CMS: fix typos in MARCXML data files

* Fixes typos in CMS data files.  (closes #195) (PR #195)

Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
UI: FIXED "Usage" panel in CMS Tools
UI: URL section for ex.links in "Tools" collection

* (addresses #197)
UI: real file descriptions in templates

* FIX - if no file description exists -> hide field (closes #204)
Rearrange resources to move VISPA up
CMS: number of events for PAT tuple records

* Updates CMS Derived Datasets PAT tuple records with precise
  information about number of events and total byte size.
  (closes #222)

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
CMS: embed event display in `/visualise/events`

* Embeds event display in `/visualise/events`.
  (closes #84) (closes #208) (closes #126) (PR #232)

Tested-by: Tibor Simko <tibor.simko@cern.ch>
UI: Simplifying "For Education"

* (addresses #218)
UI: Simplifying "For Education" - new intro tab

* adds new “Introduction” page to “Education” (addresses #234)
UI: URL changes  -> /getting-started/<experiment>

* (addresses #223)
UI: FIXED broken VM link

* (closes #235)
docs: richer project documentation

* Adds new "Contributing" guide explaining how to contribute in various
  ways.

* Adds new "Developing" guide intended for developers.  Enriches the
  instructions WRT installing, updating, or repopulating the site.

* Amends introductory "README" file accordingly.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
CMS: connects CMSValidatedRuns<->CMS + portalboxes