Use only one .gitignore file (root)

[olavis]

Describe Problem

It's hard to get an overview if someone is looking to determine if/why particular files are part of the repository. Most people will probably not even consider to look through multiple files in multiple locations, especially since a .gitignore file already exists in the most common location (root).

Suggest Changes

reference all ignored files in a single .gitignore file in root