Add actions/spelling config

.github/actions/spelling configuration was added for the
@check-spelling/check-spelling action.

Changelist:
- .github/actions/spelling
  - Add allow.txt with new allowed words
  - Add excludes.txt to exclude files based on common glob patterns
  - Add patterns.txt to ignore URLs, paths, configs, etc.

Additional Notes:
Spelling (minor):
An additional expect.txt file will have to be added in order to
accommodate incorrect words found in files or comments will have to be
added to those lines.

.github/actions/spelling/allow.txt

@@ -8,6 +8,7 @@ codebase
 codecov
 codefactor
 codeowner
+CODEOWNERS
 codeql
 conda
 config
@@ -25,6 +26,7 @@ deepsource
 dirname
 Django
 docstring
+docstrings
 doi
 epidemiologists
 epispot
@@ -41,6 +43,7 @@ google
 homepage
 html
 http
+https
 ICU
 img
 infecteds
@@ -99,6 +102,7 @@ sys
 timerange
 timespans
 timestep
+timesteps
 toml
 towardsdatascience
 ubuntu
@@ -112,6 +116,7 @@ versionadded
 vscode
 Website
 workflow
+workflows
 www
 xml
 yml

.github/actions/spelling/excludes.txt

@@ -0,0 +1,18 @@
+# Ignore directories named `third_party`
+(?:^|/)third_party/
+# Ignore npm files
+(?:^|/)package(?:-lock|)\.json$
+# Ignore files named (yarn for Node.js) `yarn.lock`
+(?:^|/)yarn\.lock$
+# Ignore files or directories that case-insensitively have `LICENSE` somewhere in their path
+(?:(?i)LICENSE)
+# Ignore files ending in...
+\.pdf$
+\.png$
+# Ignore Excel files (`.xsl` and `.xslx`)
+\.xslx?$
+# Ignore locales that aren't en / en_GB (roughly: keep en_US and drop everything else)
+locales/(?!en)
+locales/en_GB
+# Ignore the action's configuration data
+^\.github/action/spelling/

.github/actions/spelling/patterns.txt

@@ -0,0 +1,96 @@
+# This file contains various spellcheck patterns for @check-spelling/check-spelling
+# and is used in the spellcheck workflow. See ../../workflows/spellcheck.yml for more information.
+
+# marker to ignore all code on line
+^.*/\* #no-spell-check-line \*/.*$
+# marker for ignoring a comment to the end of the line
+// #no-spell-check.*$
+
+# git index header
+index [0-9a-z]{7,40}\.\.[0-9a-z]{7,40}
+
+# data urls
+(['"])data:.*?\g{-1}
+data:[-a-zA-Z=;:/0-9+]*,\S*
+
+# Any `http://` or `https://` URL
+https?://*
+
+# GitHub SHAs
+\bapi.github\.com/repos/[^/]+/[^/]+/[^/]+/[0-9a-f]+\b
+(?:\[[0-9a-f]+\]\(https:/|)/github\.com/[^/]+/[^/]+(?:/[^/]+/[0-9a-f]+(?:[-0-9a-zA-Z/#.]*|)\b|)
+\bgithub\.com/[^/]+/[^/]+[@#][0-9a-f]+\b
+# githubusercontent
+/[-a-z0-9]+\.githubusercontent\.com/[-a-zA-Z0-9?&=_\/.]*
+# gist github
+/gist\.github\.com/[^/]+/[0-9a-f]+
+# git.io
+\bgit\.io/[0-9a-zA-Z]+
+# GitHub JSON
+"node_id": "[-a-zA-Z=;:/0-9+]*"
+# Contributor
+\[[^\]]+]\(?:https://github\.com/[^/]+\)
+
+# bit.ly
+\bbit\.ly/\w+
+
+# gravatar
+\bgravatar\.com/avatar/[0-9a-f]+
+
+# medium
+link\.medium\.com/[a-zA-Z0-9]+
+
+# Slack
+slack://[a-zA-Z0-9?&=]+
+\bslack\.com/[-0-9a-zA-Z/_]*
+
+# stackexchange -- https://stackexchange.com/feeds/sites
+\b(?:askubuntu|serverfault|stack(?:exchange|overflow)|superuser).com/questions/\d+/[a-z-]+
+
+# URL escaped characters
+\%[0-9A-F]{2}
+# c99 hex digits (not the full format, just one I've seen)
+0x[0-9a-fA-F](?:\.[0-9a-fA-F]*|)[pP]
+# sha256
+sha256:[0-9a-f]+
+# sha-... -- uses a fancy capture
+(['"]|")[0-9a-f]{40,}\g{-1}
+# hex in url queries
+=[0-9a-fA-F]+&
+# PGP
+\b(?:[0-9A-F]{4} ){9}[0-9A-F]{4}\b
+# hex digits including css/html color classes:
+(?:[\\0][xX]|\\u|[uU]\+|#x?|\%23)[0-9a-fA-FgGrR_]{2,}(?:[uU]?[lL]{0,2}|u\d+)\b
+# uuid:
+[<({"'>][0-9a-fA-F]{8}-(?:[0-9a-fA-F]{4}-){3}[0-9a-fA-F]{12}[<'"})>]
+
+# Input to GitHub JSON
+content: "[-a-zA-Z=;:/0-9+]*="
+
+# python f-string https://www.python.org/dev/peps/pep-0498/
+\bf'
+
+# Regular expressions for (P|p)assword
+\([A-Z]\|[a-z]\)[a-z]+
+
+# JavaScript regular expressions
+/.*/[gim]*\.test\(
+\.replace\(/[^/]*/[gim]*\s*,
+
+# the negative lookahead here is to allow catching 'templatesz' as a misspelling
+# but to otherwise recognize a Windows path with \templates\foo.template or similar:
+\\templates(?![a-z])
+# ignore long runs of a single character:
+\b([A-Za-z])\g{-1}{3,}\b
+
+# Compiler flags
+[\t >"`](?:-J|)-[DPWXY]
+[\t "`]-[DPWXYLl]
+# curl arguments
+\b(?:\\n|)curl(?:\s+-[a-zA-Z]+)+
+# set arguments
+\bset\s+-[abefiuox]+\b
+# tar arguments
+\b(?:\\n|)tar(?:\s+-[a-zA-Z]+|\s[a-z]+)+
+# macOS temp folders
+/var/folders/\w\w/\w+/T/