doc/go1.17: document encoding/binary.Uvarint max read of 10 bytes

Updates #41185
For #44513.
Fixes #46009

Change-Id: I60f4d891b897809765acc0aace037c78e95bb4f7
Reviewed-on: https://go-review.googlesource.com/c/go/+/317929
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
Reviewed-by: Keith Randall <khr@golang.org>

Author: odeke-em

doc/go1.17.html

@@ -303,7 +303,10 @@ <h3 id="minor_library_changes">Minor changes to the library</h3>
 <dl id="encoding/binary"><dt><a href="/pkg/encoding/binary/">encoding/binary</a></dt>
   <dd>
     <p><!-- CL 299531 -->
-      TODO: <a href="https://golang.org/cl/299531">https://golang.org/cl/299531</a>: limit bytes read by Uvarint to &lt;= 10
+      <code>binary.Uvarint</code> will stop reading after <code>10 bytes</code> to avoid
+      wasted computations. If more than <code>10 bytes</code> are needed, the byte count returned is <code>-11</code>.
+      <br />
+      Previous Go versions could return larger negative counts when reading incorrectly encoded varints.
     </p>
   </dd>
 </dl><!-- encoding/binary -->