The key has been changed in the API itself.
Revert "The key has been changed in the API itself."

This reverts commit 2f753f876ceeb6a97e746743df32eda236f17dab.
Make note of Gist parameter changing in v3

Also add TOC for /v3/media
Merge pull request #211 from sigmavirus24/fix_gist

Make note of the changes for the v3 media type in gists