Implement feature to link/include other gitignore files in gitignore

Feature request:

Let .gitignore file link/include other gitignore files:

``` include .gitignore.python ```

Why would this help? https://github.com/github/gitignore/blob/main/Python.gitignore Look at how long that Python gitignore is. If I am developing a project with multiple languages, imagine how long and how many duplicates will show up when I copy templates from these other languages: https://github.com/github/gitignore . Now imagine a team of people adding new gitignore patterns. They will inevitably add them somewhere I don't want, like in the middle of templates. I don't want people editing the templates, because it's too difficult to see their changes vs the template. I want the templates to be linked so that we can tell people to copy updated gitignore templates, without having to analyze the file for lines that are custom-made.

Respectfully, consider adding this easy effective idea.