Create dbt converter for Airbyte Github source connector

The goal of this task is to ensure the Airbyte Github connector output can be used to run [Fivetran's dbt analytical model](https://hub.getdbt.com/fivetran/github/latest/).

**Definition of Done:**
* Create a pull request that adds new tables or views, enabling the execution of Fiventran's dbt with Airbyte output data.
* Update the documentation inside the connector folder to explain how to configure the user dbt package to run the analytical model.

**Resources:**
* Check example of how it was done for [Zendesk Support](link) connector