fix: replaced file existence check for shell check (spicetify#1445)

* fix: replaced file existence check for shell check

* fix: rollback `fish` change

* add: permissive check for config file

install.sh

@@ -31,8 +31,8 @@ fi
 spicetify_install="$HOME/.spicetify"
 path="export PATH=\"\$PATH:\$HOME/.spicetify\""
 
-if [[ -f "$HOME/.bashrc" ]] && ! grep -q "$path" "$HOME/.bashrc"; then echo "${path}" >>"$HOME/.bashrc" && echo "SAVING         ${spicetify_install} to \$PATH (bash)"; fi
-if [[ -f "$HOME/.zshrc" ]] && ! grep -q "$path" "$HOME/.zshrc"; then echo "${path}" >>"$HOME/.zshrc" && echo "SAVING         ${spicetify_install} to \$PATH (zsh)"; fi
+if (grep -q "bash" $SHELL || [[ -f "$HOME/.bashrc" ]]) && ! grep -q "$path" "$HOME/.bashrc"; then echo "${path}" >>"$HOME/.bashrc" && echo "SAVING         ${spicetify_install} to \$PATH (bash)"; fi
+if (grep -q "zsh" $SHELL || [[ -f "$HOME/.zshrc" ]]) && ! grep -q "$path" "$HOME/.zshrc"; then echo "${path}" >>"$HOME/.zshrc" && echo "SAVING         ${spicetify_install} to \$PATH (zsh)"; fi
 if [[ -f "$HOME/.config/fish/config.fish" ]] && ! grep -q "$path" "$HOME/.config/fish/config.fish"; then echo "${path}" >>"$HOME/.config/fish/config.fish" && echo "SAVING         ${spicetify_install} to \$PATH (fish)"; fi
 
 exe="$spicetify_install/spicetify"