Use SPDX snippet tags instead of copy-pasting full license text

Based on spdx/spdx-spec#719

zsh-history-substring-search.zsh

@@ -119,39 +119,11 @@ if [[ $+functions[_zsh_highlight] -eq 0 ]]; then
 
   #
   # The following snippet was taken from the zsh-syntax-highlighting project:
-  #
   # https://github.com/zsh-users/zsh-syntax-highlighting/blob/56b134f5d62ae3d4e66c7f52bd0cc2595f9b305b/zsh-syntax-highlighting.zsh#L126-161
   #
-  # Copyright (c) 2010-2011 zsh-syntax-highlighting contributors
-  # 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 the zsh-syntax-highlighting contributors 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.
-  #
+  # SPDX-SnippetBegin
+  # SPDX-License-Identifier: BSD-3-Clause
+  # SPDX-SnippetCopyrightText: 2010-2011 zsh-syntax-highlighting contributors
   #--------------8<-------------------8<-------------------8<-----------------
   # Rebind all ZLE widgets to make them invoke _zsh_highlights.
   _zsh_highlight_bind_widgets()
@@ -190,6 +162,7 @@ if [[ $+functions[_zsh_highlight] -eq 0 ]]; then
     done
   }
   #-------------->8------------------->8------------------->8-----------------
+  # SPDX-SnippetEnd
 
   _zsh_highlight_bind_widgets
 fi