cover workflow related apis

[amirali-ashraf]

From what I see in the repo the gem does not cover workflows and workflow_overrides. Although we are able to use the templates for the first one but it would be nice if the syntax follows the convention. Unless, I've missed something, those missing end points can be added to the gem. The following are the missing related docs: https://docs.novu.co/api-reference/workflows/ https://docs.novu.co/api-reference/workflow-overrides/ https://docs.novu.co/api-reference/workflow-groups/