feat: add progress indicator

src/main.zig

@@ -1,8 +1,8 @@
 const std = @import("std");
 
 pub fn main() !void {
-    const img_width = 512;
-    const img_height = 512;
+    const img_width = 1024;
+    const img_height = 720;
 
     var buf: [img_width * img_height * 3]u8 = undefined;
 
@@ -13,6 +13,7 @@ pub fn main() !void {
     try writer.print("P3\n{d} {d}\n255\n", .{ img_width, img_height });
     try writer.flush();
     for (0..img_height) |j| {
+        std.debug.print("\rLines remaining: {d}     ", .{img_height - j});
         for (0..img_width) |i| {
             const r = @as(f64, @floatFromInt(j)) / (img_width - 1);
             const g = 0.0;
@@ -25,5 +26,6 @@ pub fn main() !void {
             try writer.print("{d} {d} {d}\n", .{ ir, ig, ib });
         }
     }
+    std.debug.print("\rDone                                               \n", .{});
     try writer.flush();
 }