Add licensing and README

lwipopts.h

@@ -1,9 +1,30 @@
+/*
+ * Copyright 2020 (c) 2020 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.
+ */
+
 #ifndef __LWIPOPTS_H__
 #define __LWIPOPTS_H__
 
-// Common settings used in most of the pico_w examples
-// (see https://www.nongnu.org/lwip/2_1_x/group__lwip__opts.html for details)
-
 // allow override in some examples
 #ifndef NO_SYS
 #define NO_SYS                      1