Missing information in API V3 to API V4 migration guide

gitlab-ce~4107637 There was a change in API between v3 and v4 regarding raw blob contents:

• v3: GET /projects/:id/repository/raw_blobs/:sha (https://gitlab.com/gitlab-org/gitlab-ce/blob/8-16-stable/doc/api/repositories.md#raw-blob-content)
• v4: GET /projects/:id/repository/blobs/:sha/raw (https://docs.gitlab.com/ee/api/repositories.html#raw-blob-content)

While documented properly in both API version docs, this change was not mentioned in the v3 to v4 transition guide.