Add state

curl --request POST \
  --url https://api.plane.so/api/v1/workspaces/{workspace-slug}/projects/{project_id}/states/ \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '{
  "name": "<string>",
  "color": "<string>"
}'