⚡️ Accept array of string as valid input schema path.

[hsblhsn]

This PR adds a feature that accepts both string and array of string as valid input in schema key in config.

This feature is completely backward compatible. It does not deprecate or break the previous config file format.

Most of the code is sourced from https://github.com/99designs/gqlgen.

Closes #88

[csilvers]

Thanks, this look good to me!

The only thing that's needed before landing is to update docs/CHANGELOG.md, to add this new feature under ### New features:. There's also probably some documentation elsewhere in docs/ that needs to be updated to document the new yaml file format possibility.

[csilvers]

I think genqlient has its own errorf wrapper -- is it appropriate to use that here?

[hsblhsn]

is it appropriate to use that here?

You are right. Whole code should have one unified style. Pushed f471c95.

[hsblhsn]

How does this sound to you?

# The filename with the GraphQL schema (in SDL format), relative to
# genqlient.yaml. This can also be a list of filenames.
# such as:
#  schema:
#  - user.graphql
#  - ./schema/*.graphql
#  - ./another_directory/**/*.graphqls
schema: schema.graphql

It would be more specific. WDYT?

[csilvers]

How does this sound to you?

# The filename with the GraphQL schema (in SDL format), relative to
# genqlient.yaml. This can also be a list of filenames.
# such as:
#  schema:
#  - user.graphql
#  - ./schema/*.graphql
#  - ./another_directory/**/*.graphqls
schema: schema.graphql

It would be more specific. WDYT?

That looks great! It makes clear you can use glob patterns, too.

[csilvers]

Awesome! Thanks so much.

I don't know if I actually have the ability to merge this in, but hopefully someone else on this review does if I don't.

[dnerdy]

Hello @hsblhsn! Thanks for the contribution. Could you sign the Khan Academy Contributor License Agreement when you have a moment?