Add script admin/run-codespell and supporting files

* admin/codespell/README:
* admin/codespell/codespell.dictionary:
* admin/codespell/codespell.exclude:
* admin/codespell/codespell.ignore:
* admin/codespell/codespell.rc:
* admin/run-codespell: New files.

admin/codespell/README

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+This directory contains supporting files for running codespell.
+See the ./admin/run-codespell script.
+
+codespell.dictionary
+
+    This file contains additional, Emacs-specific corrections.  When
+    fixing typos in Emacs, consider adding them to this file.
+
+codespell.exclude
+
+    This file contains lines that are correct and should be ignored by
+    codespell.  Add any false positives to this file.
+
+    The lines must match lines in the Emacs source tree exactly,
+    including any whitespace.
+
+codespell.ignore
+
+    This file contains any words that are correct in the context of
+    Emacs, or that we otherwise choose to ignore.  Use your best
+    judgment when adding words to this file.  Common typos that are
+    only correct in highly specific contexts should probably be in
+    codespell.exclude instead.
+
+codespell.rc
+
+    This file contains the Emacs specific codespell configuration.

admin/codespell/codespell.dictionary

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+alis->alist, alias, alas, axis, alms,
+boostrap-clean->bootstrap-clean
+brunches->branches
+defalis->defalias
+defalises->defaliases
+ecmacs->emacs
+ehsell->eshell
+emcs->emacs
+finis->finish
+firs->first
+file-writeable-p->file-writable-p
+hep->help
+least-favourite->least-favorite
+lien->line
+liens->lines
+mecas->emacs
+sehell->eshell, shell,

admin/codespell/codespell.ignore

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+acknowledgements
+afile
+ake
+analogue
+ans
+bloc
+blocs
+callint
+clen
+crossreference
+crossreferences
+debbugs
+dedented
+dependant
+doas
+ede
+grey
+gud
+ifset
+inout
+keypair
+keyserver
+keyservers
+lightening
+mapp
+master
+mimicks
+mitre
+msdos
+ot
+parm
+parms
+reenable
+reenabled
+requestor
+sie
+spawnve
+statics
+stdio
+texline
+typdef

admin/codespell/codespell.rc

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+[codespell]
+skip=.git/*,*.elc,*.eln,*.gpg,*.gz,*.icns,*.jpg,*.kbx,*.key,*.pbm,*.png,*.rnc,*.so,*.tiff,*.tit,*.xml,*.xpm,*.zip,*random_seed
+builtin=clear,rare,en-GB_to_en-US
+quiet-level=35

admin/run-codespell

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+#!/bin/bash
+### run-codespell - run codespell on Emacs
+
+## Copyright (C) 2023-2024 Free Software Foundation, Inc.
+
+## Author: Stefan Kangas <stefankangas@gmail.com>
+
+## This file is part of GNU Emacs.
+
+## GNU Emacs is free software: you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation, either version 3 of the License, or
+## (at your option) any later version.
+
+## GNU Emacs is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+
+## You should have received a copy of the GNU General Public License
+## along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+### Commentary:
+
+## Run codespell on the Emacs source tree.
+##
+## codespell 2.2.2 or later is recommended.  Earlier versions had a
+## bug where the line count was incorrect for files containing "^L"
+## characters.
+
+source "${0%/*}/emacs-shell-lib"
+
+CODESPELL_DIR="${PD}/codespell"
+
+CODESPELL_RC="${CODESPELL_DIR}/codespell.rc"
+CODESPELL_EXCLUDE="${CODESPELL_DIR}/codespell.exclude"
+CODESPELL_IGNORE="${CODESPELL_DIR}/codespell.ignore"
+CODESPELL_DICTIONARY="${CODESPELL_DIR}/codespell.dictionary"
+
+emacs_run_codespell ()
+{
+    git ls-files |\
+        grep -v -E -e '^(lib|m4)/.*' |\
+        grep -v -E -e '^admin/(charsets|codespell|unidata)/.*' |\
+        grep -v -E -e '^doc/misc/texinfo.tex$' |\
+        grep -v -E -e '^etc/(AUTHORS|HELLO|publicsuffix.txt)$' |\
+        grep -v -E -e '^etc/refcards/(cs|de|fr|pl|pt|sk)-.+.tex$' |\
+        grep -v -E -e '^etc/tutorials/TUTORIAL\..+' |\
+        grep -v -E -e '^leim/(MISC|SKK)-DIC/.*' |\
+        grep -v -E -e '^lisp/language/ethio-util.el' |\
+        grep -v -E -e '^lisp/ldefs-boot.el' |\
+        grep -v -E -e '^lisp/leim/.*' |\
+        grep -v -E -e '^test/lisp/net/puny-resources/IdnaTestV2.txt' |\
+        grep -v -E -e '^test/manual/(etags|indent)/.*' |\
+        grep -v -E -e '^test/src/regex-resources/.*' |\
+        xargs codespell \
+              --config "$CODESPELL_RC" \
+              --exclude-file "$CODESPELL_EXCLUDE" \
+              --ignore-words "$CODESPELL_IGNORE" \
+              --disable-colors \
+              --write-changes \
+              $@
+}
+
+emacs_run_codespell
+emacs_run_codespell --dictionary "$CODESPELL_DICTIONARY"
+
+exit 0