Update README.md - private variables

Follow up to casey#2300

README.md

@@ -1739,7 +1739,7 @@ Recipes, `mod` statements, and aliases may be annotated with attributes that cha
 | `[no-exit-message]`<sup>1.7.0</sup> | recipe | Don't print an error message if recipe fails. |
 | `[no-quiet]`<sup>1.23.0</sup> | recipe | Override globally quiet recipes and always echo out the recipe. |
 | `[positional-arguments]`<sup>1.29.0</sup> | recipe | Turn on [positional arguments](#positional-arguments) for this recipe. |
-| `[private]`<sup>1.10.0</sup> | alias, recipe | Make recipe or alias private. See [Private Recipes](#private-recipes). |
+| `[private]`<sup>1.10.0</sup> | alias, recipe | Make recipe, alias, or variable private. See [Private Recipes](#private-recipes). |
 | `[script]`<sup>1.33.0</sup> | recipe | Execute recipe as script. See [script recipes](#script-recipes) for more details. |
 | `[script(COMMAND)]`<sup>1.32.0</sup> | recipe | Execute recipe as a script interpreted by `COMMAND`. See [script recipes](#script-recipes) for more details. |
 | `[unix]`<sup>1.8.0</sup> | recipe | Enable recipe on Unixes. (Includes MacOS). |