Add mergeready tag to CONTRIBUTING
Add mergeready tag to CONTRIBUTING

Using a mergeready tag tells others (repo owner in particular) that the
changes are finished and are ready to be merged to master.  Without this
indication it may be unclear whether changes should be merged or if more
work or fixes are coming.

nivertech/duktape,zeropool/duktape,tassmjau/duktape,chenyaqiuqiu/duktape,harold-b/duktape,harold-b/duktape,nivertech/duktape,nivertech/duktape,harold-b/duktape,tassmjau/duktape,zeropool/duktape,tassmjau/duktape,svaarala/duktape,zeropool/duktape,markand/duktape,chenyaqiuqiu/duktape,nivertech/duktape,chenyaqiuqiu/duktape,chenyaqiuqiu/duktape,zeropool/duktape,jmptrader/duktape,harold-b/duktape,nivertech/duktape,jmptrader/duktape,zeropool/duktape,nivertech/duktape,tassmjau/duktape,markand/duktape,markand/duktape,jmptrader/duktape,jmptrader/duktape,zeropool/duktape,tassmjau/duktape,svaarala/duktape,jmptrader/duktape,harold-b/duktape,tassmjau/duktape,jmptrader/duktape,nivertech/duktape,harold-b/duktape,tassmjau/duktape,svaarala/duktape,tassmjau/duktape,markand/duktape,svaarala/duktape,zeropool/duktape,jmptrader/duktape,markand/duktape,jmptrader/duktape,harold-b/duktape,nivertech/duktape,svaarala/duktape,markand/duktape,svaarala/duktape,chenyaqiuqiu/duktape,tassmjau/duktape,nivertech/duktape,chenyaqiuqiu/duktape,zeropool/duktape,markand/duktape,harold-b/duktape,svaarala/duktape,svaarala/duktape,chenyaqiuqiu/duktape,chenyaqiuqiu/duktape,svaarala/duktape,chenyaqiuqiu/duktape,harold-b/duktape,zeropool/duktape,tassmjau/duktape,jmptrader/duktape,markand/duktape,nivertech/duktape,harold-b/duktape,chenyaqiuqiu/duktape,zeropool/duktape,jmptrader/duktape,markand/duktape,markand/duktape