Problem:
NVIM_APPNAME does not allow path separators in the name, so relative
paths can't be used:
NVIM_APPNAME="neovim-configs/first-config" nvim
NVIM_APPNAME="neovim-configs/second-config" nvim
Solution:
Let NVIM_APPNAME be a relative path. Absolute paths are not supported.
fix#23056fix#24966