runtime(sh): Update sh syntax and add shDerefOffset to shDerefVarArray for bash (#13480) Commit: https://github.com/vim/vim/commit/ce3b0136c6d9d09af41969d3dc9634f115505a32 Author: Lucien Grondin <grondilu@yahoo.fr> Date: Sat Nov 4 09:41:37 2023 +0100 runtime(sh): Update sh syntax and add shDerefOffset to shDerefVarArray for bash (https://github.com/vim/vim/issues/13480) Add shDerefOffset to shDerefVarArray. Example code: ```bash declare -a a=({a..z}) echo "${a[@]:1:3}" ``` Signed-off-by: Christian Brabandt <cb@256bit.org>