fix(contrib/util): use /usr/bin/env shebang for bash scripts
docs(troubleshooting): use double backticks for inline literals
docs(troubleshooting): add "could not find unit template" section
Merge pull request #2562 from mboersma/could-not-find-unit

Add "could not find unit template" section to troubleshooting docs
Merge pull request #2561 from mboersma/manveru-master

fix(contrib/util): use /usr/bin/env shebang for bash scripts
feat(deisctl): add -ssh-timeout command-line option