update README to mention multi-core loading
update README to mention multi-core loading

bgruening/gemini,heuermh/gemini,brentp/gemini,brentp/gemini,bpow/gemini,bgruening/gemini,xuzetan/gemini,udp3f/gemini,arq5x/gemini,bpow/gemini,xuzetan/gemini,bpow/gemini,udp3f/gemini,xuzetan/gemini,bgruening/gemini,bw2/gemini,xuzetan/gemini,udp3f/gemini,heuermh/gemini,heuermh/gemini,bw2/gemini,bw2/gemini,bw2/gemini,udp3f/gemini,arq5x/gemini,arq5x/gemini,arq5x/gemini,brentp/gemini,bgruening/gemini,brentp/gemini,heuermh/gemini,bpow/gemini