exclude css files from duplicate word sanity check.  enable selector quoting sanity check with implemented exclusion.

Fix SC2145: Argument mixes string and array. Use * or separate argument.
Fix SC2162: read without -r will mangle backslashes.
Fix SC2086: Double quote to prevent globbing and word splitting.
Fix SC2164: Use 'cd ... || exit' or 'cd ... || return' in case cd fails.