UI: changes CMS text for Research description

* amends CMS description text until parallel-big-file-download is safe
* (addresses #377)
* (closes #587)
ALICE: updates ALICE Learning Resources page

* (closes #384)
collections: updates collections template

* updates breadcrumbs for parent-current collection
* html escaping for collection description
* lightens font-weight in collection desc links
UI: adds Learning Resources "action"-box to homepg
Add link to CMS Tools (Closes #592)
Make "datasets" lowercase in subheader
Remove mention of JSON file in validated runs