Move showNumber to TS and call showString (#829)

libs/core/basic.ts

@@ -0,0 +1,15 @@
+namespace basic {
+    
+    /**
+     * Scroll a number on the screen. If the number fits on the screen (i.e. is a single digit), do not scroll.
+     * @param interval speed of scroll; eg: 150, 100, 200, -100
+     */
+    //% help=basic/show-number
+    //% weight=96
+    //% blockId=device_show_number block="show|number %number" blockGap=8
+    //% async
+    //% parts="ledmatrix" interval.defl=150
+    export function showNumber(value: number, interval?: number) {
+        showString(value.toString(), interval);
+    }
+}