Bump date in copyright notice

Better late than never.
2021-01-30 09:33:07 +01:00 · 2021-01-30 09:33:07 +01:00 · c6af10f216
--- a/README.org
+++ b/README.org
@ -95,6 +95,6 @@ it.

 * License

-ⓒ 2017–2020 Daniel Borchmann
+ⓒ 2017–2021 Daniel Borchmann

 This configuration is available under the MIT license, see [[LICENSE]] for details.