Basic escaping: & and < and > and "...

Here's a test with some higher-order unicode characters to escape...

Given we're dealing almost exclusively with english it's probably OK to escape 言葉 like この言葉。

Here's some currency characters: $€¥¢£₨

Here's some arrows: ☚⇝⇥⇡⇞⥥⬇⬆⬅➡