Improved: adds an OFBiz-Online-Documentation.adoc file.txt

This is for persons who prefer to start from source rather than site or wiki

Also while at it fixes a typo in CONTRIBUTING.adoc

CONTRIBUTING.adoc

@@ -16,7 +16,7 @@ KIND, either express or implied.  See the License for the
 specific language governing permissions and limitations
 under the License.
 ////
-[[conributing]]
+[[contributing]]
 = Contributing to Apache OFBiz®
 
 https://cwiki.apache.org/confluence/display/OFBIZ/Apache+OFBiz+Contribution+and+Development

OFBiz-Online-Documentation.adoc

@@ -0,0 +1,22 @@
+////
+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.
+////
+[[documentationOnline]]
+= OFBiz® documentation online
+
+https://nightlies.apache.org/ofbiz/trunk/