Meta: "set up" ReadableStreams instead of "create"

Follows whatwg/streams#1110. Closes whatwg#1205.

fetch.bs

@@ -5181,12 +5181,13 @@ optional boolean <var>forceNewConnection</var> (default false), run these steps:
  <li><p>Let <var>sizeAlgorithm</var> be an algorithm that accepts a <a>chunk</a> object and returns
  a non-negative, non-NaN, non-infinite number, chosen by the user agent.
 
- <li><p>Let <var>stream</var> be the result of <a for=ReadableStream>creating</a> a
- {{ReadableStream}} with <a for=ReadableStream/create><var>pullAlgorithm</var></a> set to
- <var>pullAlgorithm</var>, <a for=ReadableStream/create><var>cancelAlgorithm</var></a> set to
- <var>cancelAlgorithm</var>, <a for=ReadableStream/create><var>highWaterMark</var></a> set to
- <var>highWaterMark</var>, and <a for=ReadableStream/create><var>sizeAlgorithm</var></a> set to
- <var>sizeAlgorithm</var>.
+ <li><p>Let <var>stream</var> be a <a>new</a> {{ReadableStream}}.
+
+ <li><p><a for=ReadableStream>Set up</a> <var>stream</var> with
+ <a for="ReadableStream/set up"><var>pullAlgorithm</var></a> set to <var>pullAlgorithm</var>,
+ <a for="ReadableStream/set up"><var>cancelAlgorithm</var></a> set to <var>cancelAlgorithm</var>,
+ <a for="ReadableStream/set up"><var>highWaterMark</var></a> set to <var>highWaterMark</var>, and
+ <a for="ReadableStream/set up"><var>sizeAlgorithm</var></a> set to <var>sizeAlgorithm</var>.
 
  <li>
   <p>Run these steps, but <a>abort when</a> the ongoing fetch is <a for=fetch>terminated</a>:
@@ -5986,7 +5987,8 @@ steps:
 
 <ol>
  <li><p>Let <var>stream</var> be <var>object</var> if <var>object</var> is a {{ReadableStream}}
- object; otherwise the result of <a for=ReadableStream>creating</a> a {{ReadableStream}}.
+ object. Otherwise, let <var>stream</var> be a <a>new</a> {{ReadableStream}}, and
+ <a for=ReadableStream>set up</a> <var>stream</var>.
 
  <li><p>Let <var>action</var> be null.