Sync sgit.sh to be sgit from sgit repo

The repo is at https://github.com/xexyl/sgit.

Changed header comments in Makefile, noting that Landon made the
Makefile (here) but that the most up to date copy of the tool can be
found at my repo noted above. This is to make it easier in case there
comes a time where I am unable to update it here right away and then
forget to do it later after updating the repo (though it seems unlikely
that this will ever need to be done I'd like this in as a safety net).

src/sgit/Makefile

@@ -1,28 +1,14 @@
 #!/usr/bin/env make
 #
-# sgit - run sed on all files under git control
+# sgit - run sed (by default with -i) on all files (or one or more globs) under
+# git control.
 #
-# Copyright (c) 2023 by Landon Curt Noll.  All Rights Reserved.
+# The most up to date version of this tool and everything related can be found
+# at https://github.com/xexyl/sgit.
 #
-# Permission to use, copy, modify, and distribute this software and
-# its documentation for any purpose and without fee is hereby granted,
-# provided that the above copyright, this permission notice and text
-# this comment, and the disclaimer below appear in all of the following:
+# - Cody Boone Ferguson / @xexyl
 #
-#       supporting documentation
-#       source copies
-#       source works derived from this source
-#       binaries derived from this source or from derived source
-#
-# LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
-# INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
-# EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
-# CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
-# USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
-# OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
-# PERFORMANCE OF THIS SOFTWARE.
-#
-# chongo (Landon Curt Noll, http://www.isthe.com/chongo/index.html) /\oo/\
+# This Makefile was created by Landon Curt Noll.
 #
 # Share and enjoy! :-)
 

src/sgit/sgit.sh

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 #
-# sgit - run sed on all files under git control
+# sgit - run sed (by default with -i) on all files (or one or more globs) under
+# git control
 #
 # This script allows one to run sed under git control without having to come up
 # with a list of files first and then passing those to the command.