message: chore: overhaul eslintignore file
diff: -packages/graphiql/test/vendor
  +################################################################################
  +#
  +# First things first; we need to ignore our built files. To achive this, we
  +# have to do a bit of an ignore dance where we ignore everything, and then
  +# specifically un-ignore the source code, configuration files, etc.
  +#
  +# First: ignore FILES (not folders!)
  +/packages/**/*.js
  +/packages/**/*.jsx
  +/packages/**/*.ts
  +/packages/**/*.tsx
  +#
  +# Now un-ignore source code, tests, configuration, etc
  +!/packages/*/src/**
  +!/packages/*/test/**
  +!/packages/codemirror-graphql/resources/**
  +!/packages/examples/**
  !.eslintrc.js
  -**/node_modules/**
  -**/flow-typed/**
  -**/dist/**
  -node_modules
  -packages/graphiql/graphiql.*
  +!babel.config.js
  +#
  +# End of the ignore dance.
  +#
  +################################################################################
  +
  +# Regular eslintignore configuration follows.
  +
  +# ESLint automatically ignores node_modules _in the root_, so we only need to specify nested node_modules
  +**/node_modules
  +
  +# Build artifacts
  +**/flow-typed
  +**/dist
  +
  +# Vendored files
  +/packages/graphiql/test/vendor
  