No URL for "[3] CitrixAuth Authentication Scheme v1"

[guyrleech]

The other two footnotes have URLs, this one doesn't so looking up the authentication scheme involves a search rather than direct click.

Docs URL:https://developer-docs.citrix.com/projects/storefront-services-api/en/latest/

[davidgreen99]

Merged PR citrix/storefront-store-services-api#1 to add link in footnote