Update index.md
Update index.md

Removed link to SKY API Console docs in Basics section (not relevant at this point in Payments API Beta).
Updated GET Merchant account list operation name for consistency and accuracy.
blackbaud/sky-api-docs,blackbaud/sky-api-docs,blackbaud/sky-api-docs,blackbaud/sky-api-docs,blackbaud/sky-api-docs