Add tasks for all the new languages

Task/Temperature-conversion/Sidef/temperature-conversion.sidef

@@ -0,0 +1,12 @@
+var scale = Hash(
+    Celcius    => Hash.new(factor => 1  , offset => -273.15 ),
+    Rankine    => Hash.new(factor => 1.8, offset =>    0    ),
+    Fahrenheit => Hash.new(factor => 1.8, offset => -459.67 ),
+);
+
+var kelvin = Sys.readln("Enter a temperature in Kelvin: ").to_n;
+kelvin >= 0 || die "No such temperature!";
+
+scale.keys.sort.each { |key|
+    printf("%12s:%8.2f\n", key, kelvin*scale{key}{:factor} + scale{key}{:offset});
+}