Documentation for 0.1.0 Release

[Spartee]

Description

API documentation for the python library for redisvl. Autogenerate this using sphinx or similar tooling.

Acceptance Criteria

• Method to create barebones API documentation using a tool like sphinx
• Add documentation dependencies to [dev] extras require
• add instructions for generating documentation to README.

[Spartee]

See #21 and #19 for progress