Pressing left/right at the beginning/end of inline latex should exit the inline latex editing mode

[thesamovar]

If you have some inline latex and you are holding the right key to move through, you enter latex editing mode but continuing to hold right doesn't do anything when the cursor gets to the end of the latex bit, meaning you have to hit escape, which makes it a lot of work to move through text using keyboard alone and you resort to having to use the mouse.

[thesamovar]

@rowanc1 @stevejpurves should I be putting these here or on the main curvenote repo? This one doesn't seem to have much activity in the issues section.

[rowanc1]

Here is great for editor issues!! We will pick them up eventually. :)