Fix globbing guidance for sh/bash (#2802)

README.md

@@ -105,7 +105,7 @@ Lint all `yaml` files in `path` and all subdirectories (recursive):
 - `cfn-lint path/**/*.yaml`
 
 *Note*: If using sh/bash/zsh, you must enable globbing.
-(`setopt -s globstar` for sh/bash, `setopt extended_glob` for zsh).
+(`shopt -s globstar` for sh/bash, `setopt extended_glob` for zsh).
 
 ##### Exit Codes
 `cfn-lint` will return a non zero exit if there are any issues with your template. The value is dependent on the severity of the issues found.  For each level of discovered error `cfn-lint` will use bitwise OR to determine the final exit code.  This will result in these possibilities.