Create tests for APG design pattern example: Tri-State Checkbox (#330)

* Add tri-state checkbox APG example with modified CSS/JS references

The following CSS and JS references have been removed:

* `../../css/core.css`
* `../../js/examples.js`
* `../../js/highlight.pack.js`
* `../../js/app.js`

The following references have been modified to match the directory structure of code once added to the aria-at repo:

* `../css/checkbox.css` -> `css/checkbox.css`

The reference to https://www.w3.org/StyleSheets/TR/2016/base.css has been maintained.

* Example: remove 'Related Links' nav

* Example: update pattern href

* Example: remove links to similar examples

* Example: remove 'Keyboard Support', 'Role, Property, State, and Tabindex  Attributes' and source code sections

* Example: remove footer nav

* Example: add links before and after the tri-state checkbox for use in setup scripts

The links are implemented with an `href` attribute which references their own ID.  This pattern creates links which are valid (according to the W3C's validator) but don't move the keyboard focus if accidentally activated by a tester.

* Add references.csv

* Add commands.csv

* Example: change page title and main heading text to match wording of tests

* Add supporting setup scripts for tests

* Add tests.csv

* Generate test and review files automatically

* Correct entry for Shift+F in keys.mjs

* Add VO+Command+J and Shift+VO+Command+J to VoiceOver tests when navigating to the checkbox

* Generate test and review files automatically

* Add instructions for pressing commands multiple times to JAWS and NVDA tests when navigating to checkbox and checkbox group

* Remove blank rows from CSV files which were added by Excel

* Generate test and review files automatically

* Copy files to address merge conflicts

* Regenerate test files

* Generate test and review files automatically

* Copy files to address merge conflicts

* Regenerate test files

* Generate test and review files automatically

Co-authored-by: jscholes <[email protected]>
Co-authored-by: Isabel Del Castillo <[email protected]>
Co-authored-by: IsaDC <[email protected]>
Co-authored-by: Matt King <[email protected]>
Co-authored-by: mcking65 <[email protected]>

index.html

@@ -40,54 +40,62 @@ <h1>Test Patterns for Review</h1>
             <td><a href="./tests/checkbox/index.html">Index</a></td>
             <td><a href="./review/checkbox.html">Review</a></td>
             <td>26</td>
-            <td><a href="https://github.com/w3c/aria-at/commit/d02dd7e" target="_blank">d02dd7e Regenerate test files
+            <td><a href="https://github.com/w3c/aria-at/commit/b40864a" target="_blank">b40864a Regenerate test files
 </a></td>
           </tr>
+          <tr>
+            <td>checkbox-tri-state</td>
+            <td><a href="./tests/checkbox-tri-state/index.html">Index</a></td>
+            <td><a href="./review/checkbox-tri-state.html">Review</a></td>
+            <td>24</td>
+            <td><a href="https://github.com/w3c/aria-at/commit/" target="_blank"></a></td>
+          </tr>
           <tr>
             <td>combobox-autocomplete-both</td>
             <td><a href="./tests/combobox-autocomplete-both/index.html">Index</a></td>
             <td><a href="./review/combobox-autocomplete-both.html">Review</a></td>
             <td>30</td>
-            <td><a href="https://github.com/w3c/aria-at/commit/d02dd7e" target="_blank">d02dd7e Regenerate test files
+            <td><a href="https://github.com/w3c/aria-at/commit/b40864a" target="_blank">b40864a Regenerate test files
 </a></td>
           </tr>
           <tr>
             <td>combobox-select-only</td>
             <td><a href="./tests/combobox-select-only/index.html">Index</a></td>
             <td><a href="./review/combobox-select-only.html">Review</a></td>
             <td>38</td>
-            <td><a href="https://github.com/w3c/aria-at/commit/" target="_blank"></a></td>
+            <td><a href="https://github.com/w3c/aria-at/commit/b40864a" target="_blank">b40864a Regenerate test files
+</a></td>
           </tr>
           <tr>
             <td>menu-button-actions-active-descendant</td>
             <td><a href="./tests/menu-button-actions-active-descendant/index.html">Index</a></td>
             <td><a href="./review/menu-button-actions-active-descendant.html">Review</a></td>
             <td>26</td>
-            <td><a href="https://github.com/w3c/aria-at/commit/d02dd7e" target="_blank">d02dd7e Regenerate test files
+            <td><a href="https://github.com/w3c/aria-at/commit/b40864a" target="_blank">b40864a Regenerate test files
 </a></td>
           </tr>
           <tr>
             <td>menubar-editor</td>
             <td><a href="./tests/menubar-editor/index.html">Index</a></td>
             <td><a href="./review/menubar-editor.html">Review</a></td>
             <td>40</td>
-            <td><a href="https://github.com/w3c/aria-at/commit/d02dd7e" target="_blank">d02dd7e Regenerate test files
+            <td><a href="https://github.com/w3c/aria-at/commit/b40864a" target="_blank">b40864a Regenerate test files
 </a></td>
           </tr>
           <tr>
             <td>modal-dialog</td>
             <td><a href="./tests/modal-dialog/index.html">Index</a></td>
             <td><a href="./review/modal-dialog.html">Review</a></td>
             <td>29</td>
-            <td><a href="https://github.com/w3c/aria-at/commit/d02dd7e" target="_blank">d02dd7e Regenerate test files
+            <td><a href="https://github.com/w3c/aria-at/commit/b40864a" target="_blank">b40864a Regenerate test files
 </a></td>
           </tr>
           <tr>
             <td>tabs-manual-activation</td>
             <td><a href="./tests/tabs-manual-activation/index.html">Index</a></td>
             <td><a href="./review/tabs-manual-activation.html">Review</a></td>
             <td>29</td>
-            <td><a href="https://github.com/w3c/aria-at/commit/d02dd7e" target="_blank">d02dd7e Regenerate test files
+            <td><a href="https://github.com/w3c/aria-at/commit/b40864a" target="_blank">b40864a Regenerate test files
 </a></td>
           </tr>
     </table>