Remove broken Firehose reference (#499)

Co-authored-by: Benoît Rouleau <[email protected]>

Author: enoldev

website/pages/en/firehose/_meta.js

@@ -74,8 +74,7 @@ export default () =>
       items: {
         'design-principles': 'Design Principles',
         'firehose-starter': 'Firehose Acme',
-        'new-blockchains': 'New Blockchains',
-        'why-integrate-the-firehose': 'Why Integrate the Firehose?',
+        benefits: 'Why Integrate the Firehose',
       },
     },
     references: {