How to ignore files or subdirectories for the build


I’m using GitHub as version control system for my project. This repository does contain some documents and general information as well which at the moment cause a trigger of the build any time I commit a change.
Is their a possibility to exclude subdirectories and files specific files from triggering the build process?
I already found the [skip ci] / [ci skip] statements which are fine when entering the comment to the commit.
But is their a way to configure this in the circle.yml?
It will be quiet difficult to tell the people commiting things not as frequently to remember putting the [skip ci] in the comment.