davServer acknowledgements (#511)

ACKNOWLEDGEMENTS.md

@@ -1,5 +1,37 @@
 # ACKNOWLEDGEMENTS
 
+## github.com/openziti/zrok/drives/davServer
+
+The `davServer` package is based on code from `https://cs.opensource.google/go/go/`, which included the following license:
+
+> Copyright (c) 2009 The Go Authors. All rights reserved.
+> 
+> Redistribution and use in source and binary forms, with or without
+> modification, are permitted provided that the following conditions are
+> met:
+>
+>    * Redistributions of source code must retain the above copyright
+> notice, this list of conditions and the following disclaimer.
+>    * Redistributions in binary form must reproduce the above
+> copyright notice, this list of conditions and the following disclaimer
+> in the documentation and/or other materials provided with the
+> distribution.
+>    * Neither the name of Google Inc. nor the names of its
+> contributors may be used to endorse or promote products derived from
+> this software without specific prior written permission.
+> 
+> THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+> "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+> LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+> A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+> OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+> SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+> LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+> DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+> THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+> (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+> OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE
+
 ## github.com/openziti/zrok/drives/davClient
 
 The `davClient` package is based on code from `github.com/emersion/go-webdav`, which included the following license: