Sous formats recipe

[hectorlj]

Adds a Sous formats recipe to add default sous text formats (*see note about date formats)

This recipe will add the following custom text filters

• Basic HTML
• Full HTML
• Restricted HTML
  and their respective dependencies.

Notes

• The date formats currently in Sous are part of core's system install config so they will be automatically installed. Any other custom date formats can still be added to this recipe.
• The plain text format is part of core's filter install config so it will be automatically installed.

[laura-johnson]

Looks great, thanks @hectorlj!