Implement #81 - Sync Script Description from GitHub

* Unfocused md-editors no longer look disabled.
* Add new panel in the scriptEditMetadataPage to with inputs to enter the filepath to a markdown file to use as the script description.
* Refactored the webhook to wait on saving the script/description before sending an OK response with a list of the models changed (or an error).
* Refactored the github import code to also handle importing markdown files.
* New Properties:
    * Script.githubSyncDescription
    * Script.githubSyncSource
    * Script.githubSyncUserId
    * Script.githubSyncRepoName
    * Script.githubSyncDescriptionPath
    * Script.githubSyncSourcePath
* Automatically fill out githubSyncUserId, githubSyncRepoName, and githubSyncSourcePath when when importing from github (eg: during the webhook).
* Disable the Script.about markdown editor when set to sync with github.