-moz-force-broken-image-icon: alt text on height OR width set (#37261)

* reword and refine moz-force-broken-image-icon note

before: if height and width is set
after: if height or width is set

* Update files/en-us/web/css/-moz-force-broken-image-icon/index.md

Co-authored-by: Brian Smith <brian@smith.berlin>

* Update files/en-us/web/css/-moz-force-broken-image-icon/index.md

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

---------

Co-authored-by: Brian Smith <brian@smith.berlin>
Co-authored-by: Joshua Chen <sidachen2003@gmail.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

files/en-us/web/css/-moz-force-broken-image-icon/index.md

@@ -55,7 +55,7 @@ img {
 {{EmbedLiveSample('Examples','125','125')}}
 
 > [!NOTE]
-> Unless the image has a specified height and width the alt attribute will not be displayed if `-moz-force-broken-image-icon` is set to `1`.
+> The alt text may not be visible if `-moz-force-broken-image-icon` is set to `1` and the image has no (or too small) `height` or `width` set.
 
 ## Notes