Error in headers for Github GraphQL example

[Aonrud]

Documentation issue

Summary

The example using load_data() to fetch from the Github GraphQL API has an authentication header. The header for sending the token should be authorization as per the Github documentation.

Proposed solution

Update overview.md (line 472) to use authorization instead in case anyone else lazily cuts and pastes the example as a starting point (like I did!) and gets a failed query.

[Keats]

A PR would be nice!

[Aonrud]

Apologies – that was a bit lazy! :)

Sent a PR to master since it's a documentation correction.