added add-catacid.txt contribution
added add-catacid.txt contribution

rkaranam/patchwork,SaraHal/patchwork,cadazab/patchwork,Frankyx93/patchwork,gtbay707/patchwork,SarahSexton/patchwork,elzbeth/patchwork,laurenamy/patchwork,diegobust4545/patchwork,apound01/patchwork,joysjsj/patchwork,raju249/patchwork,juliozm20/patchwork,carufenon/patchwork,tanmiiti/patchwork,ruicorte/patchwork,Soumya08pragya/patchwork,colpac64/patchwork,Misatoteen/hello-world