doc+cli: Change sponsor link

Author: KSXGitHub

src/args.rs

@@ -21,7 +21,7 @@ use text_block_macros::text_block;
         "Summarize disk usage of the set of files, recursively for directories."
         ""
         "Copyright: Apache-2.0 © 2021 Hoàng Văn Khải <https://ksxgithub.github.io/>"
-        "Donation: https://patreon.com/khai96_"
+        "Sponsor: https://github.com/sponsors/KSXGitHub"
     },
 
     after_help = text_block! {