Link to blog posts in README.md (#2)

README.md

@@ -1,3 +1,21 @@
-`rules_go_simple` is a simple set of Bazel rules for building Go code.  It is
-intended to be a simple, clean, minimal example of how to write Bazel rules for
-new languages.
+`rules_go_simple` is a simple set of Bazel rules for building Go code.  It
+is intended to be a simple, clean, minimal example of how to write Bazel
+rules for new languages.
+
+The rules are divided into versions (v1, v2, etc.). Each version builds
+upon the last and includes all the functionality of the previous
+versions. The rules are fully commented, and the process of creating each
+version is documented in a series of blog posts at
+[jayconrod.com](https://jayconrod.com/).
+
+* **v1**: A minimal example of a rule that produces an executable
+  (`go_binary`). Described in
+  [Simple binary rule](https://jayconrod.com/posts/106/writing-bazel-rules--simple-binary-rule).
+* **v2**: Adds a small rule that produces a library
+  (`go_library`). Described in
+  [Library rule, depsets, providers](https://jayconrod.com/posts/107/writing-bazel-rules--library-rule--depsets--providers).
+* **v3**: Adds a `data` attribute. Described in
+  [Data and runfiles](https://jayconrod.com/posts/108/writing-bazel-rules--data-and-runfiles).
+* **v4**: Moves most of the implementation out of Starlark into a
+  "builder" binary. Described in
+  [Moving logic to execution](https://jayconrod.com/posts/109/writing-bazel-rules--moving-logic-to-execution).