Update readme
Update readme

Fixed spelling/grammar errors and added step to run src.exe before using opening FSM in browser
sean-callahan/factorio-server-manager,sean-callahan/factorio-server-manager,MajorMJR/factorio-server-manager,MajorMJR/factorio-server-manager,sean-callahan/factorio-server-manager,mroote/factorio-server-manager,MajorMJR/factorio-server-manager,mroote/factorio-server-manager,MajorMJR/factorio-server-manager,mroote/factorio-server-manager,mroote/factorio-server-manager,sean-callahan/factorio-server-manager