Correct way to add custom image effects to camera?

I found and modified a C# script and a shader script to achieve a certain sort of chromatic abberation effect on my camera, using them in the way described here: https://docs.unity3d.com/550/Documentation/Manual/WritingImageEffects.html

It works fine in the editor, but when I do a build, it just shows a black screen. First I thought it was just because my shader hadn't been added to the build, however it's still just black even though I added my shader to "always included". Then I saw that this method is a part of the "legacy" docs, so it's probably half or wholly deprecated, which might be why it's not working with the latest Unity version.

What is the correct way to create a custom post-processing-ish effect these days? Seems that "image effect shader" isn't even part of the current docs, and I'm pretty lost about which terms to look for?