Fix #94, Inclusion of a BSD Open-Source License text copy (#95)

- Update source code header copyright date

LICENSE.txt

@@ -0,0 +1,26 @@
+Copyright 2020-2023 Raspberry Pi (Trading) Ltd. 
+
+Redistribution and use in source and binary forms, with or without modification, 
+are permitted provided that the following conditions are met: 
+
+1. Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+
+2. 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.
+
+3. Neither the name of the copyright holder 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 HOLDER 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.

pico_project.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 
 #
-# Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+# Copyright (c) 2020-2023 Raspberry Pi (Trading) Ltd.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #