Entities in documentation's example code should be escaped

[binaryape]

Bootstrap's documentation uses entities such as "×" in its own source, but these entities are not escaped in the example code blocks, causing them to be displayed as the rendered character ("×").

When I copied and pasted the example code for alerts it triggered a unicode-related error in my software - not Bootstrap's fault, but it would be better if the entity was shown in the examples instead of the literal character.

[mdo]

Fixed this in 2.1.0-wip.