[PATCH 2/3] emacs: Add customization and hook for tach-mode to notmuch-message.el

This adds a customization option "notmuch-message-attachment-interface" to notmuch-message.el. If set to t, tach-mode will be used as an attachment interface for composing in message mode. If set to nil, it will not be used. The default is nil, but if people like it, we can default to t in the fut

[PATCH 2/3] emacs: Add customization and hook for tach-mode to notmuch-message.el

This adds a customization option "notmuch-message-attachment-interface" to notmuch-message.el. If set to t, tach-mode will be used as an attachment interface for composing in message mode. If set to nil, it will not be used. The default is nil, but if people like it, we can default to t in the fut