Merge pull request processing#7812 from dpanshug/doc-keyboard-bug

docs(keyboard): clarify keyIsDown() documentation for key codes and browser compatibility

Author: perminder-17

src/events/keyboard.js

@@ -832,10 +832,16 @@ function keyboard(p5, fn){
    * }
    * ```
    *
-   * `keyIsDown()` can check for key presses using
-   * <a href="#/p5/keyCode">keyCode</a> values, as in `keyIsDown(37)` or
-   * `keyIsDown(LEFT_ARROW)`. Key codes can be found on websites such as
-   * <a href="https://keycode.info" target="_blank">keycode.info</a>.
+   * `keyIsDown()` can check for key presses using strings based on
+   * <a href="https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/key" target="_blank">KeyboardEvent.key</a>
+   * or <a href="https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/code" target="_blank">KeyboardEvent.code</a> values,
+   * such as `keyIsDown('x')` or `keyIsDown('ArrowLeft')`.
+   *
+   * Note: In p5.js 2.0 and newer, numeric keycodes (such as 88 for 'X') are no longer supported.
+   * This is a breaking change from previous versions.
+   *
+   * You can still use the p5 constants like `LEFT_ARROW` which now map to string values
+   * internally rather than numeric codes.
    *
    * @method keyIsDown
    * @param {Number|String}   code key to check.