Fix margin for right-aligned images

[rickhanlonii]

Motivation

@cyan33 found this bug and submitted it to the Jest repo, I thought I'd put in a quick fix

Closes jestjs/jest#5299
Closes #397

Test Plan

Tested using the website/ within this project

Before:

After:

[rickhanlonii]

Sorry @cyan33, just saw #397, didn't mean to step on your toes 😔

[cyan33]

@rickhanlonii It's alright! Happy to see this get fixed! 😄

[cyan33]

On second thought tho, I think it's better to separate the imageAlignSide into imageAlignLeft and imageAlignRight. Because it seems that only adding an imageAlignRight makes the logic across those two components somewhat duplicated and not that intuitive.

[rickhanlonii]

I had the same thought, I'll update

[rickhanlonii]

Updated, that's much cleaner thanks @cyan33

[JoelMarcey]

@rickhanlonii Thank you so much for taking the time to fix this. Looks good to me.

And thanks @cyan33 for raising the issue too.

[cyan33]

@JoelMarcey No problem! 😄

[JoelMarcey]

Looks great.

At first I thought about whether imageAlignSide is actually necessary (not taking into consideration it would be a breaking change if we took it out). But I think it works like this.