adding readme mention about running from source
adding readme mention about running from source

kennethlimcp/particle-cli,spark/particle-cli,spark/particle-cli,kennethlimcp/particle-cli,spark/particle-cli,kennethlimcp/particle-cli,spark/particle-cli,spark/particle-cli,kennethlimcp/particle-cli,kennethlimcp/particle-cli,spark/particle-cli,kennethlimcp/particle-cli