fix(website) new mongo install instructions
fix(website) new mongo install instructions

Mongo has its own tap now -- see
https://github.com/Homebrew/homebrew-core/pull/43770.

rmosolgo/graphql-ruby,rmosolgo/graphql-ruby,rmosolgo/graphql-ruby,nevesenin/graphql-ruby,nevesenin/graphql-ruby,rmosolgo/graphql-ruby,nevesenin/graphql-ruby,nevesenin/graphql-ruby