fixing the comment in build.zig, replacing Debug,ReleaseSafe,ReleaseFast,ReleaseSmall mentions with debug,safe,fast,small

lib/init/build.zig

@@ -13,7 +13,7 @@ pub fn build(b: *std.Build) void {
     // for restricting supported target set are available.
     const target = b.standardTargetOptions(.{});
     // Standard optimization options allow the person running `zig build` to select
-    // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
+    // between debug, safe, fast, and small. Here we do not
     // set a preferred release mode, allowing the user to decide how to optimize.
     const optimize = b.standardOptimizeOption(.{});
     // It's also possible to define more custom flags to toggle optional features