Wrong punctuation and numbers in Persian

[ShahriarKh]

• We use » and « in Persian, not single-quotes ':
  ❌ 'هماهنگی'
  ✔ «هماهنگی»

• The correct form of semicolon in Persian is ؛, not ;.

• Correct numbers in Persian are:
  ۰ ۱ ۲ ۳ ۴ ۵ ۶ ۷ ۸ ۹ (Zero to nine, ltr like English)

  Handling Input

  This one is a little bit tricky. Some Persian keyboard layouts (like the one I use) use English digits for numbers (\u0030 ~ \u0039), some use correct Persian numbers (\u06F0 ~ \u06F9) and some use Arabic numbers (\u0660 ~ \u0669). Because of this inconsistency across user keyboards, I think the best way to handle this is to allow all unicodes, so for example, there should be no difference between ۴ (Persian Four), ٤ (Arabic Four) & 4 (English Four). Another way is to let the user enable/disable an option to treat different unicodes equally.

  Displaying

  Some fonts like Vazir Matn (as I mentioned in Better font for Persian & Arabic & Kurdish #2816), have an FD version. FD stands for Farsi (Persian) Digits. It shows the Persian form of character, no matter what you type. For example in Vazirmatn FD ۵, ٥ and 5 all are shown as ۵.