Possibility to turn on/off custom template.
Possibility to revert to default template.

Remove html template (not used any more)

For testing:

• toggle off - should be displayed default title/content template, user should not be able to modify it

• toggle on- should be displayed last modify of custom template, user should be able to modify template

• state of toggle and custom template should be possible to save

• after restore default value button, template and toggle state should be restored to its original values (custom template should has default template value)