doc: document major finished changes in v14

Added description of semver-major changes to finished in v14.

PR-URL: #33065
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

doc/api/stream.md

@@ -1486,6 +1486,21 @@ unless `emitClose` is set in false.
 ### `stream.finished(stream[, options], callback)`
 <!-- YAML
 added: v10.0.0
+changes:
+  - version: v14.0.0
+    pr-url: https://github.com/nodejs/node/pull/32158
+    description: The `finished(stream, cb)` will wait for the `'close'` event
+                 before invoking the callback. The implementation tries to
+                 detect legacy streams and only apply this behavior to streams
+                 which are expected to emit `'close'`.
+  - version: v14.0.0
+    pr-url: https://github.com/nodejs/node/pull/31545
+    description: Emitting `'close'` before `'end'` on a `Readable` stream
+                 will cause an `ERR_STREAM_PREMATURE_CLOSE` error.
+  - version: v14.0.0
+    pr-url: https://github.com/nodejs/node/pull/31509
+    description: Callback will be invoked on streams which have already
+                 finished before the call to `finished(stream, cb)`.
 -->
 
 * `stream` {Stream} A readable and/or writable stream.
@@ -1563,6 +1578,12 @@ changes:
   - version: v13.10.0
     pr-url: https://github.com/nodejs/node/pull/31223
     description: Add support for async generators.
+  - version: v14.0.0
+    pr-url: https://github.com/nodejs/node/pull/32158
+    description: The `pipeline(..., cb)` will wait for the `'close'` event
+                 before invoking the callback. The implementation tries to
+                 detect legacy streams and only apply this behavior to streams
+                 which are expected to emit `'close'`.
 -->
 
 * `source` {Stream|Iterable|AsyncIterable|Function}