add note for non-blocking file descriptor used for json_loadfd
add note for non-blocking file descriptor used for json_loadfd

akheron/jansson,Mephistophiles/jansson,Mephistophiles/jansson,markalanj/jansson,bstarynk/jansson,bstarynk/jansson,bstarynk/jansson,markalanj/jansson,akheron/jansson,markalanj/jansson,akheron/jansson