[feature] add support to free mode

[vczb]

I would like to make a slide transition and when I stop the slides should keep the position I left

I saw many issues asking for this and I don't understand why they are closed

#1988 #532

[gsmachado]

I'm also interested in the free mode feature.

Or at least to know the reasons why issues #1988 and #532 are closed without any apparent reason.

Thanks!

[pratyushbh]

Hi, apparently the free mode is not supported by the original jQuery slick carousel on which the react-slick is based on, that's why free mode is not supported by react-slick too.