Fix regexpIsVideoPost

[acochrane]

The previous regular expression statement was difficult to read and would not catch "me/videos" links.
Now it is more readable and catches any instance of "/videos".

[huandu]

The regexp should be \/videos$. The \ and $ are required. Please update your PR. Thanks.

[acochrane]

I had to escape the leading backslash, but I'm not sure if this is acceptable, being a neophyte of regular expressions.
It still works in my use case.

What do you think?

[huandu]

Your PR should work fine. It's better to use `` to quote a regular expression so that you can write `\/videos$`. Please update your PR again. Thanks.