Add entry for Drilldown to the vale dictionary

vale/dictionary/d.jsonnet

@@ -14,6 +14,7 @@ local word = import './word.jsonnet';
   word.new('DOM', '', 'noun') { abbreviation: true, elaboration: 'Document Object Model', established_abbreviation: true },
   word.new("don'ts", '', 'noun'),
   word.new('downsample', 'DG', 'verb'),
+  word.new('Drilldown', '', 'noun'),
   word.new('duplicate', 'dDSN', 'noun') { swaps: { 'de-duplicate': 'deduplicate', 'de-duplicated': 'deduplicated', 'de-duplicates': 'deduplicates', 'de-duplication': 'deduplication' } },
   word.new('Dynatrace', '', 'noun') { product: true },
   word.new('passwordless', '', 'adjective') { description: 'https://en.wikipedia.org/wiki/Passwordless_authentication' },