Wire-webapp: Syntax highlighting in Dark theme is often unreadable

[maximbaz]

Wire Desktop 3.9.2895
Arch Linux

What steps will reproduce the problem?

1. Switch to Dark theme
2. Send the following message:

````
CSS:

li:nth-child(3n)::before {
  content:'Fizz';
}
li:nth-child(5n)::after {
  content:'Buzz';
}

Python:

def main():
    print "hello world"

````

What is the expected result?

Syntax highlighting is readable

What is the actual result?

Dark-blue and grey are not readable:

[lipis]

We should use solarized
https://ethanschoonover.com/solarized/

[odiferousmint]

Or better yet, support multiple color themes! Personally I like monokai.

[lipis]

Should be fixed now!