Fix method doc signatures for multiline required parameters (#374)

* Fix method doc signatures for multiline required parameters.

Existing doc generator failed to recognize parameters as required when parameter descriptions
extended over more than one line. Besides presenting incorrect information, resulting
inconsistencies broke checks for automated sample generation.

* Regen docs
diff --git a/docs/dyn/youtube_v3.channels.html b/docs/dyn/youtube_v3.channels.html
index 72c12aa..a733962 100644
--- a/docs/dyn/youtube_v3.channels.html
+++ b/docs/dyn/youtube_v3.channels.html
@@ -75,17 +75,17 @@
 <h1><a href="youtube_v3.html">YouTube Data API</a> . <a href="youtube_v3.channels.html">channels</a></h1>
 <h2>Instance Methods</h2>
 <p class="toc_element">
-  <code><a href="#list">list(part=None, hl=None, mine=None, mySubscribers=None, id=None, managedByMe=None, onBehalfOfContentOwner=None, forUsername=None, pageToken=None, categoryId=None, maxResults=None)</a></code></p>
+  <code><a href="#list">list(part, hl=None, mine=None, mySubscribers=None, id=None, managedByMe=None, onBehalfOfContentOwner=None, forUsername=None, pageToken=None, categoryId=None, maxResults=None)</a></code></p>
 <p class="firstline">Returns a collection of zero or more channel resources that match the request criteria.</p>
 <p class="toc_element">
   <code><a href="#list_next">list_next(previous_request, previous_response)</a></code></p>
 <p class="firstline">Retrieves the next page of results.</p>
 <p class="toc_element">
-  <code><a href="#update">update(part=None, body, onBehalfOfContentOwner=None)</a></code></p>
+  <code><a href="#update">update(part, body, onBehalfOfContentOwner=None)</a></code></p>
 <p class="firstline">Updates a channel's metadata. Note that this method currently only supports updates to the channel resource's brandingSettings and invideoPromotion objects and their child properties.</p>
 <h3>Method Details</h3>
 <div class="method">
-    <code class="details" id="list">list(part=None, hl=None, mine=None, mySubscribers=None, id=None, managedByMe=None, onBehalfOfContentOwner=None, forUsername=None, pageToken=None, categoryId=None, maxResults=None)</code>
+    <code class="details" id="list">list(part, hl=None, mine=None, mySubscribers=None, id=None, managedByMe=None, onBehalfOfContentOwner=None, forUsername=None, pageToken=None, categoryId=None, maxResults=None)</code>
   <pre>Returns a collection of zero or more channel resources that match the request criteria.
 
 Args:
@@ -379,7 +379,7 @@
 </div>
 
 <div class="method">
-    <code class="details" id="update">update(part=None, body, onBehalfOfContentOwner=None)</code>
+    <code class="details" id="update">update(part, body, onBehalfOfContentOwner=None)</code>
   <pre>Updates a channel's metadata. Note that this method currently only supports updates to the channel resource's brandingSettings and invideoPromotion objects and their child properties.
 
 Args: