[Feature Request] Update file extension or editor extension to allow automatic Markdown preview

[Enteleform]

VSCode's Markdown All in One extension has a

"markdown.extension.preview.autoShowPreviewToSide"

setting that automatically opens markdown file previews to the side.  

EG:

 

Two implementations that might allow GhostText to take advantage of this functionality:

• change the .tmp extension to tmp.md

• have VSCode & other editors' GhostText extension automatically set the langage mode to Markdown

[fregante]

Same as https://github.com/GhostText/GhostText/issues/65

You can ask on the GT VS Code repo to use the correct extension