Add support for PHP::SmartyPants

[bluebirch]

Added support for PHP::SmartyPants, "a free web typography prettifyier tool for web writers. It easily translates plain ASCII punctuation characters into 'smart' typographic punctuation HTML entities" (https://michelf.ca/projects/php-smartypants/).

This functionality is controlled with the new smart configuration option.

Quotes can be customized and adapted to your preference.

I'm not a PHP developer but a psychologist, so please excuse if my code is slow and ineffective.

[danpros]

Hello,

Thanks for the pull but we should not use it. PHP markdown is enough because PHP Markdown actively developed so it's possible that this feature will be available either.

Not to mention the occurrence of conflict because it is almost the same. https://stackedit.io

[bluebirch]

PHP::SmartyPants is from the same developer and is what is recommended if you want to convert quotes and dashes in PHP::Markdown, see for example michelf/php-markdown#144 and michelf/php-markdown#146 (comment).

[bluebirch]

May I bring this feature up for discussion once again?

[danpros]

Hello,

Can you make it optional? so we can on and off it via the settings.

[bluebirch]

It is optional and turned on with smart = "true" in the configuration. Further customization is possible with doublequote.open, doublequote.close, singlequote.open and singlequote.close.

[vdbhb59]

This sure sounds like a good option. :)