Add basic README

Author: keith

README.md

@@ -0,0 +1,26 @@
+# rules_mojo
+
+This repository provides rules for building
+[Mojo](https://www.modular.com/mojo) projects using
+[Bazel](https://bazel.build).
+
+## Quick setup
+
+Copy the latest `MODULE.bazel` snippet from [the releases
+page](https://github.com/modular/rules_mojo/releases).
+
+Currently `rules_mojo` requires `bzlmod` and bazel 8.x or later.
+
+## Example
+
+```bzl
+load("@rules_mojo//mojo:mojo_binary.bzl", "mojo_binary")
+
+mojo_binary(
+    name = "hello_mojo",
+    srcs = ["hello_mojo.mojo"],
+)
+```
+
+See the [tests](https://github.com/modular/rules_mojo/tree/main/tests)
+directory for more examples.