Update reference Profiler.md (#5502)

beta/src/content/reference/react/Profiler.md

@@ -54,7 +54,7 @@ function onRender(id, phase, actualDuration, baseDuration, startTime, commitTime
 #### Parameters {/*onrender-parameters*/}
 
 * `id`: The string `id` prop of the `<Profiler>` tree that has just committed. This lets you identify which part of the tree was committed if you are using multiple profilers.
-* `phase`: Either `"mount"` or `"update"`. This lets you know whether the tree has just been mounted for the first time or re-rendered due to a change in props, state, or hooks.
+* `phase`: `"mount"`, `"update"` or `"nested-update"`. This lets you know whether the tree has just been mounted for the first time or re-rendered due to a change in props, state, or hooks.
 * `actualDuration`: The number of milliseconds spent rendering the `<Profiler>` and its descendants for the current update. This indicates how well the subtree makes use of memoization (e.g. [`memo`](/reference/react/memo) and [`useMemo`](/reference/react/useMemo)). Ideally this value should decrease significantly after the initial mount as many of the descendants will only need to re-render if their specific props change.
 * `baseDuration`: The number of milliseconds estimating how much time it would take to re-render the entire `<Profiler>` subtree without any optimizations. It is calculated by summing up the most recent render durations of each component in the tree. This value estimates a worst-case cost of rendering (e.g. the initial mount or a tree with no memoization). Compare `actualDuration` against it to see if memoization is working.
 * `startTime`: A numeric timestamp for when React began rendering the current update.