Apply a clarification to "Frame" glossary entry (#12892)

Applying a clarification/tweak that git wouldn't accept in my last PR.

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Co-authored-by: Parker Lougheed <parlough@gmail.com>

Author: sfshaza2

src/data/glossary.yml

@@ -30,12 +30,15 @@
 
 - term: "Frame"
   short_description: |-
-    A single image in a sequence of images that makes up an animation or UI update.
+    A single image in a sequence of images that
+    makes up an animation or UI update.
   long_description: |-
-    Flutter aims to produce 60 frames per second (fps), or 120 fps on capable devices.
-    This means the framework has approximately 16ms (or 8ms) to render each frame.
-    If the app takes longer than this to render a frame, the user may see
-    [jank](/resources/glossary#jank).
+    Flutter aims to produce 60 frames per second (fps),
+    or 120 fps on capable devices.
+    This means the framework has approximately 16ms (at 60 fps)
+    or 8ms (at 120 fps) to render each frame.
+    If the app takes longer than this to render a frame,
+    the user might see [jank](/resources/glossary#jank).
   related_links:
     - text: "Rendering performance"
       link: "/perf/rendering-performance"