v0.6.4

This doesn't affect comments, only other plain text within a file (eg. in YAML
files). Now blocks of plain text with differing indents are treated as separate
paragraphs. Previously a blank line was needed to separate paragraphs.

Eg: this text was treated as one paragraph but now as two.

Some text
    Some more text

Also doesn't affect markdown files, or .txt files, which are currently treated
the same as markdown.