user docs: Document Analytics feature.

Fixes #3648.

templates/zerver/help/analytics.md

@@ -0,0 +1,85 @@
+# Analytics
+
+Zulip provides [analytics](/stats) for tracking various statistics about your
+organization to create a holistic view of its communications. All graphs are
+fully updated once a day, except for the **Messages sent over time** graph,
+which is updated once an hour.
+
+## Messages sent over time
+
+![Messages sent over time](/static/images/help/messages_sent_over_time.png)
+
+This section shows the number of messages sent by organization users over a
+certain period of time in a bar graph.
+
+To view the amount of messages sent over a point of time, hover over a point
+on the graph to see its corresponding time period and message count displayed
+in the bottom left corner.
+
+By default, messages sent by **Humans** (users) each **week** are shown in the
+graph.
+
+* To change the time period that messages aggregate over, click a button next
+to the **Aggregation** label in the top left corner.
+    * Selecting the **Cumulative** option will transform the graph into a line
+    graph representing the total amount of messages sent over time.
+* To change the types of users shown in the graph, click one of the labels in
+legend in the top right corner.
+* To change the total timeframe of the graph, select an option in the bottom
+right corner of the graph.
+    * You can also choose a custom timeframes by clicking and dragging the
+  window frame as shown below.
+    ![Sliding window](/static/images/help/stats-sliding-window.png)
+
+### Messages sent by client
+
+![Messages sent by client](/static/images/help/messages_sent_by_client.png)
+
+This section shows the percentage of messages sent by organization users across
+each client (platform) over a recent time period in a bar graph.
+
+By default, messages sent by **everyone** (all users in the organization) over
+the past **month** are shown in the graph.
+
+* To change the time period of the messages shown in the graph, click one of the
+options in the second group of buttons in the bottom right corner.
+* Click the **Me** option in the first group of buttons in the bottom right
+corner to see the percentage of messages you sent with each client.
+
+### Messages sent by recipient type
+
+![Messages sent by recipient type](/static/images/help/messages_sent_by_recipient_type.png)
+
+This section shows the percentages of messages sent by organization users
+over a recent period of time according to their recipient types (public or
+private; streams, individuals, or groups) in a pie chart.
+
+The legend in the top right corner shows the percentages of each message
+recipient type; to see the specific amount of messages sent by a recipient type,
+hover over the type's portion of the pie chart.
+
+By default, messages sent by **everyone** (all users in the organization) over
+the past **month** are displayed in the graph.
+
+* To change the time period of the messages shown in the graph, click one of the
+options in the second group of buttons in the bottom right corner. The total
+amount of messages sent over time is shown in the bottom left corner.
+* Click the **Me** option in the first group of buttons in the bottom right
+corner to see the percentage of messages you sent with each client.
+
+### Active users
+
+![Active users](/static/images/help/stats-number-users.png)
+
+This section shows the amount of active users (users that logged on at least
+once within a day) across a certain period of time in a line graph. Each point
+on the graph represents the active user count for a day.
+
+To view the amount of active users on a day, hover over a point
+on the graph to see its corresponding date and active user count displayed
+in the bottom left corner.
+
+By default, the amount of active users since the creation of the organization
+(**All time**) is displayed on the graph. You can view the amount of active
+users within the last month by clicking the **Last 30 days** button to the left
+of the **All time** button in the bottom right corner.

templates/zerver/help/sidebar.md

@@ -89,6 +89,7 @@
 * [Keyboard shortcuts](/help/keyboard-shortcuts)
 * [Add a bot or integration](/help/add-a-bot-or-integration)
 * [Import users and channels from Slack](/help/import-users-and-channels-from-slack)
+* [Analytics](/help/analytics)
 
 ## Misc
 * [Tips for Zulip on Windows](/help/zulip-on-windows)