Addresses #222 Recommendations for using sudo.

[daobrien]

Would very much appreciate review by a techie person, both because of the nature of the material and also because it's a public guide and this commit touches on how we configure our courses to some degree.

[bonnevil]

I know you resolved this before I had a chance to review, but another useful classroom setup point is that we can customize the /etc/sudoers configuration for a particular course by adding files to /etc/sudoers.d, which avoids the need to make edits to the default /etc/sudoers file.

[daobrien]

I know you resolved this before I had a chance to review, but another useful classroom setup point is that we can customize the /etc/sudoers configuration for a particular course by adding files to /etc/sudoers.d, which avoids the need to make edits to the default /etc/sudoers file.

Is something you'd def like to document, and if so do you want it in the public style guide? I feel perilously close to the border of Tech Writing Style Guide and System Setup Best Practices.