Fix: Zoom enlarged by default

[ifeLawal]

[ifeLawal]

This is a fix to issue popcodeorg#1554 Zoom enlarged by default

I used a CSS media query to increase the font-size for the editor text

I assumed the iFrame text should not be increased since students have access to that via code, but just in case it would also be beneficial I tackled making the iFrame font size bigger as well by embedding a style tag in the Preview Frame source

Would love feedback and thoughts on the approach / if there should be any changes