Use double quotes as attribute
Currently pug-mode not support double quotes as HTML tag attribute, it's very inconvenient.
I try to uncomment L150 ~ L151, but I don't know what's going on with the uppercased "P" in this screenshot

Very odd. I'll look into it this weekend.
Why currently L150~L151 are commented?
Sorry for the late reply: it's commented because, at the time, it conflicted with (modify-syntax-entry ?\" "\"" table) (line 231). I'm looking into it now.
Is this still a problem? I can't recreate it. If so, could you show me the full values of the ng-options and uib-popover attributes? It's possible that the parser is choking on something within them.