Add italics support for codios

[vinayak-mehta]

Similar to how it is being done for bold and underline.

[pstuerner]

Hi, can I pick this up?

[vinayak-mehta]

Yes! Thanks :)

[vinayak-mehta]

This now depends on #59.

[pstuerner]

This might be a bigger issue. Changing codio.yaml to this

speed: 10
lines:
- prompt: $
  in: normal
  color: green
  normal: true
- prompt: $
  in: bold
  color: green
  bold: true
- prompt: $
  in: underline
  color: green
  underline: true
- prompt: $
  in: reverse
  color: green
  reverse: true

and running present codio.md on my Windows machine (cmd terminal), gives me the following:

Underline and reverse have no effect.

Furthermore, my console cannot encode the codio.yaml progress bar character (█):

Probably a separate issue. OS compatibility could be a major task.

[vinayak-mehta]

Underline and reverse have no effect.

Will have to look into which Windows terminals are supported better.

Furthermore, my console cannot encode the codio.yaml progress bar character (█): Probably a separate issue. OS compatibility could be a major task.

Yeah, I think we should also change the default progress character to a #.