ci: add check-spelling action (ohmyzsh#10470)

Co-authored-by: Josh Soref <jsoref@users.noreply.github.com>

.github/actions/spelling/README.md

@@ -0,0 +1,15 @@
+# check-spelling/check-spelling configuration
+
+File | Purpose | Format | Info
+-|-|-|-
+[dictionary.txt](dictionary.txt) | Replacement dictionary (creating this file will override the default dictionary) | one word per line | [dictionary](https://github.com/check-spelling/check-spelling/wiki/Configuration#dictionary)
+[allow.txt](allow.txt) | Add words to the dictionary | one word per line (only letters and `'`s allowed) | [allow](https://github.com/check-spelling/check-spelling/wiki/Configuration#allow)
+[reject.txt](reject.txt) | Remove words from the dictionary (after allow) | grep pattern matching whole dictionary words | [reject](https://github.com/check-spelling/check-spelling/wiki/Configuration-Examples%3A-reject)
+[excludes.txt](excludes.txt) | Files to ignore entirely | perl regular expression | [excludes](https://github.com/check-spelling/check-spelling/wiki/Configuration-Examples%3A-excludes)
+[only.txt](only.txt) | Only check matching files (applied after excludes) | perl regular expression | [only](https://github.com/check-spelling/check-spelling/wiki/Configuration-Examples%3A-only)
+[patterns.txt](patterns.txt) | Patterns to ignore from checked lines | perl regular expression (order matters, first match wins) | [patterns](https://github.com/check-spelling/check-spelling/wiki/Configuration-Examples%3A-patterns)
+[expect.txt](expect.txt) | Expected words that aren't in the dictionary | one word per line (sorted, alphabetically) | [expect](https://github.com/check-spelling/check-spelling/wiki/Configuration#expect)
+[advice.md](advice.md) | Supplement for GitHub comment when unrecognized words are found | GitHub Markdown | [advice](https://github.com/check-spelling/check-spelling/wiki/Configuration-Examples%3A-advice)
+
+Note: you can replace any of these files with a directory by the same name (minus the suffix)
+and then include multiple files inside that directory (with that suffix) to merge multiple files together.

.github/actions/spelling/advice.md

@@ -0,0 +1,25 @@
+<!-- See https://github.com/check-spelling/check-spelling/wiki/Configuration-Examples%3A-advice --> <!-- markdownlint-disable MD033 MD041 -->
+<details><summary>If the flagged items do not appear to be text</summary>
+
+If items relate to a ...
+* well-formed pattern.
+
+  If you can write a [pattern](https://github.com/check-spelling/check-spelling/wiki/Configuration-Examples:-patterns) that would match it,
+  try adding it to the `patterns.txt` file.
+
+  Patterns are Perl 5 Regular Expressions - you can [test](
+https://www.regexplanet.com/advanced/perl/) yours before committing to verify it will match your lines.
+
+  Note that patterns can't match multiline strings.
+
+* binary file.
+
+  Please add a file path to the `excludes.txt` file matching the containing file.
+
+  File paths are Perl 5 Regular Expressions - you can [test](
+https://www.regexplanet.com/advanced/perl/) yours before committing to verify it will match your files.
+
+  `^` refers to the file's path from the root of the repository, so `^README\.md$` would exclude [README.md](
+../tree/HEAD/README.md) (on whichever branch you're using).
+
+</details>

.github/actions/spelling/excludes.txt

@@ -0,0 +1,41 @@
+# See https://github.com/check-spelling/check-spelling/wiki/Configuration-Examples:-excludes
+(?:^|/)(?i)COPYRIGHT
+(?:^|/)(?i)LICEN[CS]E
+(?:^|/)package(?:-lock|)\.json$
+(?:^|/)vendor/
+ignore$
+\.avi$
+\.ico$
+\.jpe?g$
+\.lock$
+\.map$
+\.min\..
+\.mod$
+\.mp[34]$
+\.png$
+\.wav$
+^\.github/
+^\Qplugins/archlinux/archlinux.plugin.zsh\E$
+^\Qplugins/cp/cp.plugin.zsh\E$
+^\Qplugins/extract/_extract\E$
+^\Qplugins/genpass/genpass.plugin.zsh\E$
+^\Qplugins/gitignore/gitignore.plugin.zsh\E$
+^\Qplugins/gnu-utils/gnu-utils.plugin.zsh\E$
+^\Qplugins/hitchhiker/fortunes/hitchhiker\E$
+^\Qplugins/jhbuild/jhbuild.plugin.zsh\E$
+^\Qplugins/jhbuild/README.md\E$
+^\Qplugins/jruby/jruby.plugin.zsh\E$
+^\Qplugins/kubectl/kubectl.plugin.zsh\E$
+^\Qplugins/lol/lol.plugin.zsh\E$
+^\Qplugins/mosh/mosh.plugin.zsh\E$
+^\Qplugins/npx/npx.plugin.zsh\E$
+^\Qplugins/powder/_powder\E$
+^\Qplugins/suse/suse.plugin.zsh\E$
+^\Qplugins/thor/_thor\E$
+^\Qplugins/universalarchive/_universalarchive\E$
+^\Qplugins/vagrant/vagrant.plugin.zsh\E$
+^\Qplugins/wp-cli/README.md\E$
+^\Qplugins/wp-cli/wp-cli.plugin.zsh\E$
+^\Qthemes/clean.zsh-theme\E$
+^\Qthemes/philips.zsh-theme\E$
+^\Qthemes/tonotdo.zsh-theme\E$