Neovim compe GraphQL schema completion source

• Link to YouTube video: https://www.youtube.com/c/CodeSmell
• See compe_gql_schema.lua for usage
• This also serves as a real-world example of making a custom nvim-compe completion source
• Note: nvim-compe is deprecated. See todo and link below.

TODOS

• Refactor for nvim-cmp → see warning on nvim-compe repo
• Make into actual plugin