The Problem: Until now, I create a IIS website/app using the IIS manager tool. The problem is that changes to a IIS website aren't documented as they should be. For example: when I update the URL Rewrite rules this changes should be documented in a version control solution.
What is your solution to solve this issus?
Using a source control is possible in any project type, including "Website" or "Web Application" projects. Are you going to establish a Continuous Integration?
Yes, you can have your project in source control. Then create a build in PowerShell and/or MSBuild that can deploy your website to a clean IIS (or at least with all dependencies there). That will document the steps needed to deploy your site.