fix: Disable user select of content

[obany]

Description of change

A user can drag select all the content in the app, this applies -user-select: none to the root of the app.

Links to any relevant issues

Fixes #338

Type of change

• Bug fix (a non-breaking change which fixes an issue)

How the change has been tested

Tested on windows

Change checklist

Add an x to the boxes that are relevant to your changes, and delete any items that are not.

• I have followed the contribution guidelines for this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes