Fix misspelling and minor cleanup of schain docs

[mike-chowla]

Type of change

• Bugfix
• Feature
• New bidder adapter
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Does this change affect user-facing APIs or examples documented on http://prebid.org?
• Other: Documentation change

Description of change

Fix misspelling
Change sample call to use hp = 1 since that's the only valid value in the current version of the spec

• contact email of the adapter’s maintainer
• official adapter submission

For any changes that affect user-facing APIs or example code documented on http://prebid.org, please provide:

• A link to a PR on the docs repo at https://github.com/prebid/prebid.github.io/

Other information