Remove other binaries. Add README.

Author: rabbah

tests/dat/actions/README.md

@@ -0,0 +1,33 @@
+<!--
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+-->
+
+### Building test artifacts
+
+Some test artifacts should be build ahead of actually running the tests.
+These test artifacts compile source code into binaries, generate JAR files,
+install modules and package functions into zip files.
+
+A `build.sh` script is availble as a convenience and will run ahead of tests
+when using `gradle`. However this script will not work on Windows as it currently
+assumes Bash is available.
+
+Some artifacts are not build because they require additional tooling.
+Specifically, these are the unicode tests for the Ballerina and .NET runtimes.
+These unicode tests are checked however in their corresponding runtime build.
+