* WIP
* Add config_template field to Device
* Pre-fetch referenced templates
* Correct up_to_date callable
* Add config_template FK to Device
* Update & merge migrations
* Add config_template FK to Platform
* Add tagging support for ConfigTemplate
* Catch exceptions when rendering device templates in UI
* Refactor ConfigTemplate.render()
* Add support for returning plain text content
* Add ConfigTemplate model documentation
* Add feature documentation for config rendering