Document that middleware functions need to return a Result object

[pmcclory-pp]

In order to propagate results through the middleware call chain each middleware needs to return a Result object. make this clear in the comments/documentation. In most cases simply propagating the Result that was returned to it by the inner layer it called

[pmcclory-pp]

@bougyman feel free to update as you see fit - just trying to capture the issue AIUI