Amend Notices for Non-Endorsement (ECP-WarpX#4924)

Amend and move NOTICES to NOTICE.txt.

Appended Text:

Reference herein to any specific commercial product, process, or service
by trade name, trademark, manufacturer, or otherwise does not necessarily
constitute or imply its endorsement, recommendation, or favoring by the
United States Government, The Regents of the University of California, or
Lawrence Berkeley National Laboratory.

The views and opinions of authors expressed herein do not necessarily
state or reflect those of the United States Government,
The Regents of the University of California, or
Lawrence Berkeley National Laboratory, and shall not be used for advertising
or product endorsement purposes.

NOTICE.txt

@@ -0,0 +1,19 @@
+This Software was developed under funding from the U.S. Department
+of Energy and the U.S. Government consequently retains certain rights. As
+such, the U.S. Government has been granted for itself and others acting on
+its behalf a paid-up, nonexclusive, irrevocable, worldwide license in the
+Software to reproduce, distribute copies to the public, prepare derivative
+works, and perform publicly and display publicly, and to permit other to do
+so.
+
+Reference herein to any specific commercial product, process, or service
+by trade name, trademark, manufacturer, or otherwise does not necessarily
+constitute or imply its endorsement, recommendation, or favoring by the
+United States Government, The Regents of the University of California, or
+Lawrence Berkeley National Laboratory.
+
+The views and opinions of authors expressed herein do not necessarily
+state or reflect those of the United States Government,
+The Regents of the University of California, or
+Lawrence Berkeley National Laboratory, and shall not be used for advertising
+or product endorsement purposes.

README.md

@@ -56,13 +56,6 @@ If you have questions about your rights to use or distribute this software,
 please contact Berkeley Lab's Innovation & Partnerships Office at
 [email protected].
 
-NOTICE.  This Software was developed under funding from the U.S. Department
-of Energy and the U.S. Government consequently retains certain rights. As
-such, the U.S. Government has been granted for itself and others acting on
-its behalf a paid-up, nonexclusive, irrevocable, worldwide license in the
-Software to reproduce, distribute copies to the public, prepare derivative
-works, and perform publicly and display publicly, and to permit other to do
-so.
-
 Please see the full license agreement in [LICENSE.txt](LICENSE.txt).
+Please see the notices in [NOTICE.txt](NOTICE.txt).
 The SPDX license identifier is `BSD-3-Clause-LBNL`.