Document how to call the GraphQL API outside the playground

[ZeldaZach]

Closes #665

The reporter could not find how to query MTGGraphQL from their own code, or how to obtain the access token the playground asks for. The page documented the playground and mentioned a Bearer token in a subsection under it, with no endpoint URL and no path to getting a token.

docs/mtggraphql/index.md

• Endpoint — POST https://graphql.mtgjson.com/, JSON body with a query property, and a note that opening it in a browser loads the playground.
• Authorization — promoted out of the playground subsection, with numbered steps for obtaining a token (Patreon, then ask on Discord).
• Querying Outside of the Playground — a curl invocation and a fetch example. The curl command was run verbatim against the live endpoint and returns both Phelddagrif printings.
• The playground's auth subsection now links to #authorization instead of repeating the "contact us" line.

docs/faq/index.md

New entry, "How do I query the GraphQL API?", carrying the curl example and the token path and linking to /mtggraphql/#usage.

markdownlint passes and the site builds with no dead links.

One thing to flag: the endpoint currently answers unauthenticated requests, prices included. These docs say to send a token, which matches the intended policy, but anyone testing will find it works without one.

🤖 Generated with Claude Code

https://claude.ai/code/session_01Xba7S7uYsrKAVdniqNcfhS

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (c0e3035) to head (eab901c).

Additional details and impacted files

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  Coverage   100.00%   100.00%           
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  Files            1         1           
  Lines           69        69           
  Branches        27        27           
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  Hits            69        69           

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