introduce autocomplete for the page to create new activity

[siruku6]

To do this, first, it is necessary to add new table like 'template activity'. And then, introduce following module.

Module

• github
  https://github.com/yourlabs/django-autocomplete-light
• document
  https://django-autocomplete-light.readthedocs.io/en/master/
• qiita(Japanese)
  https://qiita.com/sukobuto/items/2ea0793608c0ca238367

[siruku6]

The new table 'template activity' has been already added in #51.

[siruku6]

I think it is one of the useful articles.
https://www.gitmemory.com/issue/yourlabs/django-autocomplete-light/1111/534023106

https://stackoverflow.com/questions/41966065/django-npm-and-node-packages-architecture