Ability to render code blocks to PDF

[Jaqster]

Educator request - he runs a Robotics Club and would like to print out some programs for the students to create. Right-click Snapshot feature will download code image as a .png Screenshot tool will render blocks as .svg (https://makecode.com/screenshot-tool) Related issue: Printing docs in color https://github.com/microsoft/pxt/issues/5449

[pelikhan]

The edu actor would like to export snippets from custom tutorial to images/pdf