Don't set global keys for user

Simplified Installation & Configuration

This patch release streamlines the package setup by removing the automatic key binding mechanism and clarifying
documentation.

Changes:

• Removed electric-list-directory-replace-list-directory defcustom variable
• Removed electric-list-directory-setup-keys function
• Removed automatic key binding at load time
• Simplified installation instructions with clear manual and use-package examples
• Added explicit notes that the C-x C-d keybinding replaces Emacs's default list-directory
• Added emoji folder icon (📁) to header line
• Maintained autoload configuration for lazy loading

The package now follows standard Emacs package conventions where users explicitly configure their preferred
keybindings rather than having the package automatically modify global keybindings.

v1.4.0 – Fix visiting behavior on RET

electric-list-directory 1.4: fix visiting behavior on RET

• RET on a file now opens it and stays in that buffer; popup closes
  without restoring window configuration
• q/SPC still restore previous layout
• RET on a directory still drills in