in zero-input-punctuation-full-map

update doc

- add bug report link in README
- update intro doc for melpa
- add melpa badge in README
- add punctuation doc in README
- other minor doc updates

- add bug report link in README;
- add melpa badge in README;
- update intro doc in zero-input.el.in, this is used as melpa pkg
  description.

use string for input method name in `zero-input-ims'.

updated docstring for some variables.

capital letter + dot + digit is now supported in auto convert.

to match the package name. update doc in README file.

once when the code is moved into a function.

This feature is enabled by default.
To turn off this feature,

  (setq zero-input-auto-fix-dot-between-numbers nil)

for zero-input-pinyin.

zero-pinyin now uses zero-input-pinyin-build-candidates-unified
to fetch candidates. It is a unified interface, supports both
sync and async mode.

sometimes after GetCandidate dbus call, zero-input-fetch-size and
zero-input-candidates is not updated. This was because the async
function callback didn't update the metadata in some places.

- update initial fetch size and fetch size to be 1+ candidates needed for
  target page.
- removed zero-input-build-candidates-complete function,
  each async call should have its own callback function, don't reuse this one.
  in callback function, post GetCandidate metadata should be updated.

a bug is introduced in v2.0.2 defvar-local change.
the zero-input-full-width-p variable need to have a buffer local binding
when zero-input-mode is enabled. right away, not on first set.

and zero-input-toggle alias

zero-input-toggle-full-width-mode > zero-input-toggle-full-width

- dropped Package-Version metadata.
- zero-input-full-width-mode renamed to zero-input-full-width-p.
- zero-input-toggle is now an obsolete alias for zero-input-mode.
- use `defvar-local' when variable is always buffer local.
- moved test data to debug/test files.
- fixed typo. zero-input-pinin-service > `zero-input-pinyin-service'.

since this is a backward incompatible change, I set version to v2.0.0.
all symbols and functions is now prefixed with zero-input.

This change is suggested by melpa reviewer.