Add STP subscription check and composer_actions/list

[MrKevinOConnell]

New endpoints:

• fetchComposerActions -> https://docs.neynar.com/reference/composer-list grabs composer actions available.

• fetchSubscriptionCheck -> https://docs.neynar.com/reference/subscription-check fetches subscription status for a list of addresses, based off a contract address and chain id

misc:

• set up docs to generate stp changes