This ensures that `KITTY_SHELL_INTEGRATION` is manually set to the
user's `shellIntegration.mode`. This is necessary because sometimes
the variable is not set in subshells or splits.
`shellIntegration.mode` is also now ensured to always contain `no-rc`.
Kitty provides integrations for bash, fish and zsh. The new
programs.kitty.shellIntegration options allow the configuration of
these integrations.
See <https://sw.kovidgoyal.net/kitty/shell-integration> for more details.
Signed-off-by: Sefa Eyeoglu <contact@scrumplex.net>