Add release section to README.md.

RELNOTES: None.
PiperOrigin-RevId: 264566990
Change-Id: I2e86798ce0da8d7a4ac058f85627407bc0362803

README.md

diff --git a/README.md b/README.md
index 46492e1..db6df3e 100644
--- a/README.md
+++ b/README.md
@@ -5,3 +5,10 @@
 The source code of the Bazel Tools for Java is currently checked in the [bazel
 repository](https://github.com/bazelbuild/bazel). The source code will be moved 
 incrementally to this repository.
+
+# Releases
+
+The releases can be found under [java_tools/releases](https://github.com/bazelbuild/java_tools/releases)
+starting with java_tools javac11 v4.0.
+For previous releases see the issues marked with
+[the release label](https://github.com/bazelbuild/java_tools/issues/15).