Fix string inside string, and special character highlighting

[matthewtuby]

Please, check on a more complex/rich code, whether or not further syntax highlighting issues are present.

[fubuloubu]

Hey @matthewtuby! Thank you for contributing this!

However, I can't seem to notice a difference when trying this with this contract:
https://github.com/iearn-finance/yearn-vaults/blob/7df3e77d6ae52f098e80f0fbc424f96473a2790c/contracts/Vault.vy#L2-L36

Do you have an example of what this looks like in practice? It actually seems like that comment could be a misnomer, as I have quotes in a docstring working just fine there

[matthewtuby]

Right one is the original, left one after adding the changes.
Nice to see that this breaks at certain cases like block comments, wouldn't found those without you pointing it out.

Will try to fix it

[fubuloubu]

Nice! No idea how to test this stuff lol

[fubuloubu]

@matthewtuby is this okay to merge? no idea why I didn't merge yet lol

[matthewtuby]

Haven't managed to resolve the issue shown in the image above.
At this point, I gave up on the cause.
Can be merged, although it's not a solution but a tradeoff.