* Improve wording of LINTER_RULES_PATH docs (#1634).
* Add a template config file for ShellCheck (#1633).
Instruct ShellCheck to search SCRIPTDIR, the directory that the script
being linted is in, for other scripts that are sourced. Otherwise, the
commonly-used source command results in linter error SC1091. See
https://github.com/koalaman/shellcheck/wiki/SC1091 for more details.
* fix line ending
Co-authored-by: Lukas Gravley <admiralawkbar@github.com>