docs: fix decorator to reflect multiple decorators
docs: fix decorator to reflect multiple decorators

* docs/language/api.rst: the `with-decorator' builtin supports multiple
  decorators which it applies in order. Docs are updated to reflect this

tianon/hy,ALSchwalm/hy,zackmdavis/hy,larme/hy,tianon/hy,kirbyfan64/hy,timmartin/hy,larme/hy,kartikm/hy,farhaven/hy,farhaven/hy,adamfeuer/hy,freezas/hy,jakirkham/hy,paultag/hy,tuturto/hy,Tritlo/hy,aisk/hy,farhaven/hy,tianon/hy,michel-slm/hy,larme/hy,kirbyfan64/hy,Foxboron/hy,Foxboron/hy,mtmiller/hy,aisk/hy,aisk/hy,algernon/hy,gilch/hy