update release doc

  open zero-input.el file

  M-x checkdoc

  M-x package-lint-current-buffer

- make a git commit.

- push commits

- test zero-input.el in a fresh emacs -Q window.

  (load-file "~/.emacs.d/elpa/s-1.11.0/s.elc")

  (byte-compile-file "~/lisp/elisp/zero/zero-input.el" t)

  (global-set-key (kbd "<f1>") 'zero-input-mode)

  (zero-input-set-default-im 'pinyin)

  now in some buffer,

  press F1 and start typing.

- make a git commit in master branch.

- copy zero-input.el over to pkg branch.

  make a git commit in pkg branch.

  tag it if it is a stable release.

- push commits.

  push tags if it is a stable release.

** 2019-10-10 documents

- Using of D-Bus

  https://www.gnu.org/software/emacs/manual/html_mono/dbus.html