fromChildPath

Given some arbitrary path, find the Kobweb folder associated with it, climbing up the ancestor tree to do so.

So for example, "my-project/.kobweb/a/b/c/d.txt" will return "my-project" for "d.txt"

The file may itself be under the Kobweb folder, or it may be a normal file that lives inside a Kobweb project. This method will return the Kobweb folder for all cases.