Improve the initial presentation on the first run

[OmkoBass]

Hey, I've previously used Manim and I wanted to try out Animotion, it looks great.

I installed it but I saw a blank screen and had no idea what's happening. Everything was just dark, no errors in the console and no responsiveness.

I thought that the project was not working properly. After about five minutes I figured out that the controls property inside the options prop is actually set to false.

I'd suggest that we just add a simple text saying that to see the presentation, use your arrow keys or space bar or something like that. Since maybe newer people that try this out will just click away and think "This is not working"

I'll see if I have enough time to open a PR for this.

Btw, this is a great tool! Great job!

[mattcroat]

@OmkoBass I agree, so I enabled controls by default and added text for clarity. 👍️