docs: Add 'sort by function' to Quick Reference page

Author: claremacrae

docs/Quick Reference.md

@@ -44,7 +44,7 @@ This table summarizes the filters and other options available inside a `tasks` b
 | `has tags`<br>`no tags`<br>`tag (includes, does not include) <tag>`<br>`tags (include, do not include) <tag>`<br>`tag (regex matches, regex does not match) /regex/i`<br>`tags (regex matches, regex does not match) /regex/i`                                                                                                                        | `sort by tag`<br>`sort by tag <tag_number>` | `group by tags`        | `hide tags`            | `task.tags`                                                                                                                    |
 |                                                                                                                                                                                                                                                                                                                                                       |                                             |                        |                        | `task.originalMarkdown`                                                                                                        |
 | **[[About Scripting\|Scripting]]**                                                                                                                                                                                                                                                                                                                    |                                             |                        |                        |                                                                                                                                |
-| `filter by function`                                                                                                                                                                                                                                                                                                                                  |                                             | `group by function`    |                        |                                                                                                                                |
+| `filter by function`                                                                                                                                                                                                                                                                                                                                  | `sort by function`                          | `group by function`    |                        |                                                                                                                                |
 | **[[Combining Filters]]**                                                                                                                                                                                                                                                                                                                             |                                             |                        |                        |                                                                                                                                |
 | `(filter 1) AND (filter 2)`                                                                                                                                                                                                                                                                                                                           |                                             |                        |                        |                                                                                                                                |
 | `(filter 1) OR (filter 2)`                                                                                                                                                                                                                                                                                                                            |                                             |                        |                        |                                                                                                                                |