docs: docs update (#911)

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Fixes #<issue_number_goes_here> 🦕
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+<html><body>
+<style>
+
+body, h1, h2, h3, div, span, p, pre, a {
+  margin: 0;
+  padding: 0;
+  border: 0;
+  font-weight: inherit;
+  font-style: inherit;
+  font-size: 100%;
+  font-family: inherit;
+  vertical-align: baseline;
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+
+body {
+  font-size: 13px;
+  padding: 1em;
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+h1 {
+  font-size: 26px;
+  margin-bottom: 1em;
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+h2 {
+  font-size: 24px;
+  margin-bottom: 1em;
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+h3 {
+  font-size: 20px;
+  margin-bottom: 1em;
+  margin-top: 1em;
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+
+pre, code {
+  line-height: 1.5;
+  font-family: Monaco, 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Lucida Console', monospace;
+}
+
+pre {
+  margin-top: 0.5em;
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+
+h1, h2, h3, p {
+  font-family: Arial, sans serif;
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+h1, h2, h3 {
+  border-bottom: solid #CCC 1px;
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+.toc_element {
+  margin-top: 0.5em;
+}
+
+.firstline {
+  margin-left: 2 em;
+}
+
+.method  {
+  margin-top: 1em;
+  border: solid 1px #CCC;
+  padding: 1em;
+  background: #EEE;
+}
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+.details {
+  font-weight: bold;
+  font-size: 14px;
+}
+
+</style>
+
+<h1><a href="dialogflow_v2.html">Dialogflow API</a> . <a href="dialogflow_v2.projects.html">projects</a> . <a href="dialogflow_v2.projects.agent.html">agent</a> . <a href="dialogflow_v2.projects.agent.environments.html">environments</a></h1>
+<h2>Instance Methods</h2>
+<p class="toc_element">
+  <code><a href="dialogflow_v2.projects.agent.environments.users.html">users()</a></code>
+</p>
+<p class="firstline">Returns the users Resource.</p>
+
+<p class="toc_element">
+  <code><a href="#list">list(parent, pageToken=None, pageSize=None, x__xgafv=None)</a></code></p>
+<p class="firstline">Returns the list of all non-draft environments of the specified agent.</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>
+<h3>Method Details</h3>
+<div class="method">
+    <code class="details" id="list">list(parent, pageToken=None, pageSize=None, x__xgafv=None)</code>
+  <pre>Returns the list of all non-draft environments of the specified agent.
+
+Args:
+  parent: string, Required. The agent to list all environments from.
+Format: `projects/&lt;Project ID&gt;/agent`. (required)
+  pageToken: string, Optional. The next_page_token value returned from a previous list request.
+  pageSize: integer, Optional. The maximum number of items to return in a single page. By default 100 and
+at most 1000.
+  x__xgafv: string, V1 error format.
+    Allowed values
+      1 - v1 error format
+      2 - v2 error format
+
+Returns:
+  An object of the form:
+
+    { # The response message for Environments.ListEnvironments.
+    &quot;environments&quot;: [ # The list of agent environments. There will be a maximum number of items
+        # returned based on the page_size field in the request.
+      { # Represents an agent environment.
+        &quot;name&quot;: &quot;A String&quot;, # Output only. The unique identifier of this agent environment.
+            # Format: `projects/&lt;Project ID&gt;/agent/environments/&lt;Environment ID&gt;`.
+            # For Environment ID, &quot;-&quot; is reserved for &#x27;draft&#x27; environment.
+        &quot;description&quot;: &quot;A String&quot;, # Optional. The developer-provided description for this environment.
+            # The maximum length is 500 characters. If exceeded, the request is rejected.
+        &quot;agentVersion&quot;: &quot;A String&quot;, # Optional. The agent version loaded into this environment.
+            # Format: `projects/&lt;Project ID&gt;/agent/versions/&lt;Version ID&gt;`.
+        &quot;state&quot;: &quot;A String&quot;, # Output only. The state of this environment. This field is read-only, i.e., it cannot be
+            # set by create and update methods.
+        &quot;updateTime&quot;: &quot;A String&quot;, # Output only. The last update time of this environment. This field is read-only, i.e., it
+            # cannot be set by create and update methods.
+      },
+    ],
+    &quot;nextPageToken&quot;: &quot;A String&quot;, # Token to retrieve the next page of results, or empty if there are no
+        # more results in the list.
+  }</pre>
+</div>
+
+<div class="method">
+    <code class="details" id="list_next">list_next(previous_request, previous_response)</code>
+  <pre>Retrieves the next page of results.
+
+Args:
+  previous_request: The request for the previous page. (required)
+  previous_response: The response from the request for the previous page. (required)
+
+Returns:
+  A request object that you can call &#x27;execute()&#x27; on to request the next
+  page. Returns None if there are no more items in the collection.
+    </pre>
+</div>
+
+</body></html>
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