How do I manually configure the Link module? I would like to be able to add the file:// protocol to the list of filter_protocols so that we can add links to shared company files on a mapped drive from within our intranet website, but I'm not sure how to do this. Right now, it is apparently not included, according to Link Module Overview. Is there a way to manually configure this list in order to add file://?
You can override that in a container services file.

For example, create/edit /sites/default/services.yml, and add/alter the following lines:

parameters:
  filter_protocols:
    - http
    - https
    - ftp
    - news
    - nntp
    - tel
    - telnet
    - mailto
    - irc
    - ssh
    - sftp
    - webcal
    - rtsp
    - file


and make sure you have this line uncommented/added to settings.php:

$settings['container_yamls'][] = $app_root . '/' . $site_path . '/services.yml';