docs(contrib): remove systemd files

CONTRIBUTORS.markdown

@@ -1,6 +1,11 @@
-# CONTRIBUTORS
+# Contributors
 
-- Favonia (@favonia) contributed the majority of the code and its documentation.
-- Brandon @skarekrow) provided a sample OpenBSD `rc.d` script.
-- Thomas (@symgryph) provided sample `systemd` configuration files.
+- Favonia @favonia contributed the majority of the code and its documentation.
+- Brandon @skarekrow provided a sample OpenBSD `rc.d` script.
+
+# Past Contributors
+
+The contributions of the following people were removed when the license was changed from “Apache 2.0” to “Apache 2.0 _with LLVM exceptions”._
+
+- Thomas @symgryph provided sample `systemd` configuration files.
 - @JvdMaat helped improve [`README`](./README.markdown).

README.markdown

@@ -105,7 +105,7 @@ CLOUDFLARE_API_TOKEN=YOUR-CLOUDFLARE-API-TOKEN \
 
 ## 🏁 Deployment as a System Service
 
-See [community-contributed sample configurations](./contrib/README.markdown) for systemd and OpenBSD.
+See [community-contributed sample configurations](./contrib/README.markdown) for OpenBSD.
 
 ## 🐋 Deployment with Docker Compose
 

contrib/README.markdown

@@ -1,12 +1,5 @@
 # Community Contributions
 
-## 🆗 systemd
-
-_(contributed by [Thomas @sumgryph](https://github.com/symgryph))_
-
-- See [cloudflare-ddns.service](./systemd/cloudflare-ddns.service) for a sample systemd service unit file.
-- See [cloudflare-ddns.service.env](./systemd/cloudflare-ddns.service.env) for a sample systemd environment file.
-
 ## 🐡 OpenBSD
 
 _(contributed by [Brandon @skarekrow](https://github.com/skarekrow))_