I Have the Solution

But I really don't like the text editor for this forum so I created a Gist instead.

The Gist is both a "how-to" for installing Dockerfile Language Support, as well as an overview of importing/installing packages from TextMate and Sublime Text 3.

TLDR:

You can download the package below (view Gist for instructions) and extract it to your Local #Textastic Directory to install the Language & Syntax Definitions.

Download: dockerfile.tmbundle.zip

I can't endorse this enough.

I'm constantly working in Markdown documents for...

• README files
• Wiki pages
• Guides
• Template Generation
• etc

The overwhelming majority of my Markdown docs are meant for GitHub, and those that aren't are either meant for implementation in Jekyll pages or are just miscellaneous documents.

Adding your own GFM Preview, or implementing a system by which we can do it ourselves would be golden for me- and I'm sure the majority of your users would appreciate some kind of Markdown preview style.

I strongly second this and can't overestimate how helpful this would be or how often I would use it.