fix(neopixel-matrix): missing docstring

The docstring for `rowSpacing` property was misplaced

Author: urish

src/neopixel-matrix-element.ts

@@ -32,6 +32,7 @@ export class NeopixelMatrixElement extends LitElement {
   /**
    * The spacing between two adjacent rows, in mm
    */
+  @property({ attribute: 'rowspacing' }) rowSpacing = 1;
 
   /**
    * The spacing between two adjacent columns, in mm
@@ -53,8 +54,6 @@ export class NeopixelMatrixElement extends LitElement {
    */
   @property() animation = false;
 
-  @property({ attribute: 'rowspacing' }) rowSpacing = 1;
-
   private pixelElements: Array<[SVGElement, SVGElement, SVGElement, SVGElement]> | null = null;
 
   private animationFrame: number | null = null;