Add some more comments

c/sdl/hello_sdl.zig

@@ -5,6 +5,11 @@
// Resources:
// - http://wiki.libsdl.org/CategoryAPI
// - https://www.libsdl.org/projects/SDL_ttf/docs/SDL_ttf.html
//
// Unrelatedly, https://ziglang.org/learn/samples/ lead me to
// raylib, which looks like a really neat library to get started with
// game programming without Godot or Unity:
// https://github.com/raysan5/raylib
const c = @cImport({
    @cInclude("SDL2/SDL.h");
    @cInclude("SDL2/SDL_ttf.h");
@@ -71,6 +76,8 @@ pub fn main() !void {
        // thanks to https://stackoverflow.com/questions/22886500/how-to-render-text-in-sdl2 for some actually useful code here
        const white: c.SDL_Color = c.SDL_Color{ .r = 255, .g = 255, .b = 255, .a = 255 };
        const black: c.SDL_Color = c.SDL_Color{ .r = 0, .g = 0, .b = 0, .a = 255 };
        // Shaded vs Solid gives a nicer output, with solid the output
        // was squiggly and not aligned with a baseline.
        const text = c.TTF_RenderUTF8_Shaded(font, msg, white, black);
        _ = c.SDL_BlitSurface(text, null, surface, null);