Piccolo-admin

------

When ``piccolo_admin`` is installed, an ``admin_demo`` script is made available
on the command line, which launches a Piccolo Admin demo.

It wasn't working due to a missing folder, which has now been fixed.

-------------------------------------------------------------------------------

------

Fixed a bug with custom forms - under some situations they would fail to
render. Thanks to sinisaos for discovering this issue. See
`PR 208 <https://github.com/piccolo-orm/piccolo_admin/pull/208>`_ for more
info.

-------------------------------------------------------------------------------

------

Improved the French translations (courtesy LeMeteore).

-------------------------------------------------------------------------------

------

Added translations for simplified Chinese characters (courtesy mnixry).

-------------------------------------------------------------------------------

------

The media endpoints now obey the ``read_only`` option of ``create_admin``.
Read only mode is used for online demos.

Thanks to sinisaos for adding this.

-------------------------------------------------------------------------------

------

Added media upload support - to both a local folder, and S3.

Images, videos, PDFs, and audio files can be viewed within the UI.

This is the one of the biggest updates we've ever made!

Thanks to sinisaos for all of the help.

-------------------------------------------------------------------------------