help: Offer links to "Recent conversations" for logged in users.

- Replaces Markdown include with `{relative|message|recent}`.

help/include/open-recent-conversations.md

@@ -1 +0,0 @@
-1. Click **Recent conversations** in the left sidebar.

help/include/reading-topics.md

@@ -2,7 +2,7 @@
 
 {tab|via-recent-conversations}
 
-{!open-recent-conversations.md!}
+{relative|message|recent}
 
 1. Click on the name of a topic in the **Topic** column.
 

help/include/recent-conversations.md

@@ -6,7 +6,7 @@ for catching up on messages sent while you were away.
 
 {start_tabs}
 
-{!open-recent-conversations.md!}
+{relative|message|recent}
 
 1. The filters at the top help you quickly find relevant conversations.
    For example, select **Participated** to narrow to the topics you

help/marking-messages-as-read.md

@@ -73,7 +73,7 @@ stream or topic as read**.
 
 {tab|via-recent-conversations}
 
-{!open-recent-conversations.md!}
+{relative|message|recent}
 
 1. Click on an unread messages counter in the **Topic** column to mark all
    messages in that topic as read.

zerver/lib/markdown/help_relative_links.py

@@ -75,9 +75,15 @@ scheduled_instructions = """
    sidebar. If you do not see this link, you have no scheduled messages.
 """
 
+recent_instructions = """
+1. Click on <i class="fa fa-clock-o"></i> **Recent conversations** in the left
+   sidebar.
+"""
+
 message_info = {
     "drafts": ["Drafts", "/#drafts", draft_instructions],
     "scheduled": ["Scheduled messages", "/#scheduled", scheduled_instructions],
+    "recent": ["Recent conversations", "/#recent", recent_instructions],
 }