enhance(website) Type Merging docs

[gmac]

Expands the Schema stitching -> Type merging guide with a large set of narrative examples that walk through merging patterns. The existing tech notes are still included at the bottom under the Custom merge resolvers heading. The new guide captures a large portion of the conversation in #1874.

Sorry for the departure from User -> Chirps here! I needed an example that included two of something to analyze the query performance associated with different merging patterns.

Also has notes on the latest merging features, including field-level selectionSets (see #1888).

TODO:

• If this PR is a new feature, reference an issue where a consensus about the design was reached (not necessary for small changes)
• Make sure all of the significant new logic is covered by tests
• Rebase your changes on master so that they can be merged easily
• Make sure all tests and linter rules pass

[gmac]

Hmm, looks like that canary build is still failing for doc-only PRs.

[ardatan]

Thanks @gmac ! That's awesome! No worries for canary release job.

[theguild-bot]

The latest changes of this PR are available as alpha in npm: 6.0.19-alpha-1b1f4b65.0

Quickly update your package.json by running:

npx match-version @graphql-tools 6.0.19-alpha-1b1f4b65.0

[gmac]

@ardatan – thank you! Is the [deploy_website] prefix still operational? None of the new stitching docs are reflected on the live site.

[ardatan]

@gmac The script was broken but right now it's fixed :) So your changes are reflected now