Add a few missing meta description tags.

templates/integrations/add_pdc.html

@@ -3,6 +3,9 @@
 
 {% block title %}PagerDuty Integration for {% site_name %}{% endblock %}
 
+{% block description %}
+    <meta name="description" content="Use {% site_name %} with PagerDuty: configure {% site_name %} to create a PagerDuty incident when a check goes down, and resolve it when a check goes back up.">
+{% endblock %}
 
 {% block content %}
 <div class="row">

templates/integrations/add_pushover_help.html

@@ -3,6 +3,10 @@
 
 {% block title %}Pushover Integration for {% site_name %}{% endblock %}
 
+{% block description %}
+    <meta name="description" content="Use {% site_name %} with Pushover: configure {% site_name %} to send Pushover notifications when a checks go up or down.">
+{% endblock %}
+
 {% block content %}
 <div class="row">
 <div class="col-sm-12">

templates/integrations/add_slack_btn.html

@@ -3,6 +3,10 @@
 
 {% block title %}Slack Integration for {% site_name %}{% endblock %}
 
+{% block description %}
+    <meta name="description" content="Use {% site_name %} with Slack: configure {% site_name %} to post status updates directly to a Slack channel.">
+{% endblock %}
+
 {% block content %}
 <div class="row">
 <div class="col-sm-12">

templates/integrations/add_telegram.html

@@ -3,6 +3,9 @@
 
 {% block title %}Telegram Integration for {% site_name %}{% endblock %}
 
+{% block description %}
+    <meta name="description" content="Use {% site_name %} with Telegram: configure {% site_name %} to post status updates to a Telegram chat or user.">
+{% endblock %}
 
 {% block content %}
 <div class="row">