[docs] Improve and automate apache source releases (#8584)

RELEASING/set_release_env.sh

@@ -0,0 +1,38 @@
+#!/bin/bash
+#
+# 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.
+#
+usage() {
+   echo "usage: . set_release_env.sh <SUPERSET_VERSION> <SUPERSET_RC> <PGP_KEY_FULLBANE>"
+}
+
+if [ -z "$1" ] || [ -z "$2" ] || [ -z "$3" ]; then
+  usage;
+else
+  export SUPERSET_VERSION="${1}"
+  export SUPERSET_RC="${2}"
+  export SUPERSET_PGP_FULLNAME="${3}"
+  export SUPERSET_VERSION_RC="${SUPERSET_VERSION}rc${SUPERSET_RC}"
+  export SUPERSET_RELEASE=apache-superset-incubating-"${SUPERSET_VERSION}"
+  export SUPERSET_RELEASE_RC=apache-superset-incubating-"${SUPERSET_VERSION_RC}"
+  export SUPERSET_RELEASE_TARBALL="${SUPERSET_RELEASE}"-source.tar.gz
+  export SUPERSET_RELEASE_RC_TARBALL="${SUPERSET_RELEASE_RC}"-source.tar.gz
+
+  echo -------------------------------
+  echo Set Release env variables
+  env | grep SUPERSET
+  echo -------------------------------
+fi