Improvement for JSMN_PARENT_LINKS

[MacGritsch]

Would it make sense to insert a "template" in the header for JSMN_PARENT_LINKS? Something like this:

//  To enable JSMN_PARENT_LINKS uncomment the line below.
//  #define JSMN_PARENT_LINKS 1

[MacGritsch]

And maybe also for JSMN_STRICT, but that could also be defined in the c file instead of the header.

[pt300]

Considering that we don't have c file any more and usage of library changed to just including a .h file, I guess a small comment about those two defines could be placed at top. I'm unsure if it's really helpful though.