doc/go1.13: add more release notes for net/http

Fixes #33396

Change-Id: Id975a23b8d6555a3f19ef283fccbbe122f10acfe
Reviewed-on: https://go-review.googlesource.com/c/go/+/188477Reviewed-by: Andrew Bonventre <andybons@golang.org>

doc/go1.13.html

@@ -713,6 +713,13 @@ godoc
 
 <dl id="net/http"><dt><a href="/pkg/net/http/">net/http</a></dt>
   <dd>
+    <p><!-- CL 76410 -->
+      The new fields <a href="/pkg/net/http/#Transport.WriteBufferSize"><code>Transport.WriteBufferSize</code></a>
+      and <a href="/pkg/net/http/#Transport.ReadBufferSize"><code>Transport.ReadBufferSize</code></a>
+      allow one to specify the sizes of the write and read buffers for a <a href="/pkg/net/http/#Transport"><code>Transport</code></a>.
+      If either field is zero, a default size of 4KB is used.
+    </p>
+
     <p><!-- CL 130256 -->
       The new field <a href="/pkg/net/http/#Transport.ForceAttemptHTTP2"><code>Transport.ForceAttemptHTTP2</code></a>
       controls whether HTTP/2 is enabled when a non-zero <code>Dial</code>, <code>DialTLS</code>, or <code>DialContext</code>
@@ -729,6 +736,15 @@ godoc
       <a href="/pkg/net/http/#Pusher"><code>Pusher</code></a> and <a href="/pkg/net/http/#Flusher"><code>Flusher</code></a> interfaces.
     </p>
 
+    <p><!-- CL 157339 -->
+      The <code>StatusCode</code> <code>103</code> <code>"Early Hints"</code> has been added.
+    </p>
+
+    <p><!-- CL 167017 -->
+      On encountering unsupported transfer-encodings, <a href="/pkg/net/http/#Server"><code>http.Server</code></a> now
+      returns a "501 Unimplemented" status as mandated by the HTTP specification <a href="https://tools.ietf.org/html/rfc7230#section-3.3.1">RFC 7230 Section 3.3.1</a>.
+    </p>
+
     <p><!-- CL 167681 -->
       The new <a href="/pkg/net/http#Server"><code>Server</code></a> fields
       <a href="/pkg/net/http/#Server.BaseContext"><code>BaseContext</code></a> and
@@ -736,11 +752,26 @@ godoc
       allow finer control over the <a href="/pkg/context#Context"><code>Context</code></a> values provided to requests and connections.
     </p>
 
+    <p><!-- CL 167781 -->
+      <a href="/pkg/net/http#DetectContentType"><code>http.DetectContentType</code></a> now correctly detects RAR signatures, and can now also detect RAR v5 signatures.
+    </p>
+
     <p><!-- CL 173658 -->
       The new <a href="/pkg/net/http/#Header"><code>Header</code></a> method
       <a href="/pkg/net/http/#Header.Clone"><code>Clone</code></a> returns a copy of the receiver.
     </p>
 
+    <p><!-- CL 174324 -->
+      A new function <a href="/pkg/net/http/#NewRequestWithContext"><code>NewRequestWithContext</code></a> has been added and it
+      accepts a <a href="/pkg/context/#Context"><code>Context</code></a> that controls the entire lifetime of
+      the created outgoing <a href="/pkg/net/http/#Request"><code>Request</code></a>, suitable for use with
+      <a href="/pkg/net/http/#Client.Do"><code>Client.Do</code></a> and <a href="/pkg/net/http/#Transport.RoundTrip"><code>Transport.RoundTrip</code></a>
+    </p>
+
+    <p><!-- CL 179457 -->
+      <a href="/pkg/net/http/#Transport"><code>Transport</code></a> now silently ignores a <code>408 "Request Timeout"</code> response.
+    </p>
+
 </dl><!-- net/http -->
 
 <dl id="os"><dt><a href="/pkg/os/">os</a></dt>