Change this:

Raw HTML omitted from "/home/user/project/content/example.md"

To this:

Raw HTML omitted while rendering "/home/user/project/content/example.md"

We should change the message because markdownify and .Page.RenderString can also trigger this warning, and it may have nothing to do with anything in the content file.

Reference: https://discourse.gohugo.io/t/52280/6