Make this a GitHub Template

Signed-off-by: Christian Lindig <[email protected]>

README.md

@@ -4,7 +4,7 @@
 
 # Hello
 
-This is a minimal [OCaml] project that I use as a starting point for new
+This is a minimal [OCaml] project that I use as a [template] for new
 projects.
 
 * Top-level Makefile for convenience: just say `make` but the actual
@@ -13,9 +13,17 @@ projects.
 * GitHub Actions CI ready
 * Code is in Public Domain
 
+# Changes
+
+* This repository is a now a [GitHub] [template] repository: creating a
+  new repositoty no longer brings along its history.
+* I've changed the default branch to `main`.
+
 # Contribute
 
 If you find this useful, please contribute back by raising pull
 requests for improvements you made.
 
-[OCaml]:  https://www.ocaml.org/
+[template]:   https://docs.github.com/en/repositories/creating-and-managing-repositories/creating-a-repository-from-a-template
+[GitHub]:   https://www.github.com/
+[OCaml]:    https://www.ocaml.org/