Blockqoute generation

Hello,
I wanted to contribute to this repository and so I have followed the contributing guide and I have made a pull request to discuss the implementation.

I am using this library in a project and I acutally require *blockquote* tag generation. I have created placeholders in the code to make the pull request.

I was thinking that replacing the blockqoute start with *\n>* could be a suitable implementation and the end tag with two newlines. What do you think?