docs: add docs for outputPath configurations

[eneajaho]

Describe the problem that you experienced

Having to search github issues instead of docs for outputPath configurations

https://github.com/angular/angular-cli/issues/26304 https://github.com/angular/angular-cli/pull/26675

Enter the URL of the topic with the problem

No response

Describe what you were looking for in the documentation

How to configure the outputPath config in angular.json

Describe the actions that led you to experience the problem

No response

Describe what you want to experience that would fix the problem

No response

Add a screenshot if that helps illustrate the problem

No response

If this problem caused an exception or error, please paste it here

No response

If the problem is browser-specific, please specify the device, OS, browser, and version

No response

Provide any additional information here in as much as detail as you can

No response