Add AppVeyor badge to readme (#2341)
Add AppVeyor badge to readme (#2341)

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu
jerryscript-project/jerryscript,akosthekiss/jerryscript,LaszloLango/jerryscript,bzsolt/jerryscript,jerryscript-project/jerryscript,akosthekiss/jerryscript,bzsolt/jerryscript,robertsipka/jerryscript,jerryscript-project/jerryscript,yichoi/jerryscript,robertsipka/jerryscript,gabrielschulhof/jerryscript,LaszloLango/jerryscript,dbatyai/jerryscript,LaszloLango/jerryscript,bzsolt/jerryscript,jerryscript-project/jerryscript,zherczeg/jerryscript,dbatyai/jerryscript,zherczeg/jerryscript,dbatyai/jerryscript,zherczeg/jerryscript,yichoi/jerryscript,gabrielschulhof/jerryscript,dbatyai/jerryscript,zherczeg/jerryscript,akosthekiss/jerryscript,robertsipka/jerryscript,bzsolt/jerryscript,yichoi/jerryscript,akosthekiss/jerryscript,dbatyai/jerryscript,robertsipka/jerryscript,LaszloLango/jerryscript,LaszloLango/jerryscript,gabrielschulhof/jerryscript,robertsipka/jerryscript,yichoi/jerryscript,bzsolt/jerryscript,jerryscript-project/jerryscript,gabrielschulhof/jerryscript,akosthekiss/jerryscript,yichoi/jerryscript,robertsipka/jerryscript,gabrielschulhof/jerryscript,zherczeg/jerryscript