change to gatsby import

[tbrannam]

Code generation tool (graphql-codegen) or its dependency (graphql-tag-pluck) appear to not be able to resolve gatsby’s graphql-tag when using require. Updating these to use import syntax resolves this issue. This is the same format used by gatsby-source-contentful as well.

Without this change we are not able to reference the fragments when generating TS types.

[stefanoverna]

Thanks @tbrannam!