This option enables linebreaks to always be treated as `<br />` tags
without needing to add spaces in front of the line, the same way GitHub does.
Closes#206
When using html pre/code tags to wrap github's fenced code block syntax,
showdown would parsed them instead of treating them like plain code.
Closes#229
Fix ghCodeBlocks not being correctly parsed inside lists. Also, as a side
effect, fixes issues with consecutive lists and extra paragraphs being
added into lists.
Closes#142, Closes#183, Closes#184