zignal: export meta struct

Author: arrufat

src/zignal.zig

@@ -33,3 +33,4 @@ pub const drawLineFast = draw.drawLineFast;
 pub const drawRectangle = draw.drawRectangle;
 pub const drawPolygon = draw.drawPolygon;
 pub const fillPolygon = draw.fillPolygon;
+pub const meta = @import("meta.zig");