Empty files: missing content?

[mtbc]

There are some empty files in our documentation, e.g.,

$ find docs/1.2 -type f -empty -name \*.md | wc -l
13

Some of these may await writing. Other documents link to some of these, e.g., @suchapalaver noticed that this link fails:

$ grep sysadmin docs/1.2/index.md 
[Sysadmin Guide]({% link docs/1.2/sysadmin_guide/index.md %})
$ ls -l docs/1.2/sysadmin_guide/index.md
-rw-rw-r-- 1 mtbc mtbc 0 Jul 10 11:15 docs/1.2/sysadmin_guide/index.md