minor format fox

[wsoyinka]

minor format fix for lab 4

[github-actions]

Test results for 727b191:

Number of broken URLs: 3

URL,RESULT,FILENAME
 https://www.linode.com/docs/guides/beginners-guide-to-lxd-reverse-proxy,failed,guides/containers/lxd_web_servers.md
 https://linoxide.com/install-cockpit-on-almalinux-or-rocky-linux/,failed,guides/security/firewalld-beginners.md
 https://oktools.net/regex,failed,books/sed_awk_grep/1_regular_expressions_vs_wildcards.md

[sspencerwire]

Actually, I changed that on purpose. fuser is a command, and even though this is a heading, it should be edited as a command. This would be true even if the heading were:

### To use `fuser`

or something like that. If you look through the rest of the document, you will see similar headings for other commands.

[wsoyinka]

Oh, I see. Apologies @sspencerwire