Add D♭♭ (#961)

Author: MrBrain295

d/D♭♭

@@ -0,0 +1,5 @@
+#include <stdio.h>
+int main() {
+   printf("Hello World");
+   return 0;
+}

readme.md

@@ -270,6 +270,7 @@ Make sure to see [contributing.md](/contributing.md) for instructions on contrib
 * [DUP](d/DUP.dup)
 * [Dylan](d/Dylan.dl)
 * [Dyvil](d/Dyvil.dyv)
+* [D♭♭](d/D♭♭)
 * [E](e/E.e)
 * [e62qpodb593](e/e62qpodb593)
 * [EBuild](e/EBuild.ebuild)