feat: decode URLs when they're encoded

[stevenxxiu]

Summary

Decode encoded URL characters. This is very convenient for unicode URLs, especially say URLs including Chinese characters:

• 猫 - 维基百科，自由的百科全书

They look rather ugly otherwise in their encoded form.

Tests

• [x] Chrome stable (Linux)

[yorkxin]

I am not sure if I would agree with this, because encoding an URL is important for web servers to recognize the URL correctly. Some tricky cases include Emoji characters and special chars such as percentage mark. I myself am a native Chinese speaker, but I am not convinced to write URL in non-ASCII characters.

[yorkxin]

Here is a reference Q&A: https://stackoverflow.com/questions/13824669/how-do-you-write-a-link-containing-a-closing-bracket-in-markdown-syntax