Add colored emojis to telegram messages

so you can see whether it's up or down at first glance

templates/integrations/telegram_message.html

@@ -1,6 +1,6 @@
 {% load humanize %}
 {% if check.status == "down" %}
-The check "{{ check.name_then_code }}" is <b>DOWN</b>. Last ping was {{ check.last_ping|naturaltime }}.
+🔴 The check "{{ check.name_then_code }}" is <b>DOWN</b>. Last ping was {{ check.last_ping|naturaltime }}.
 {% else %}
-The check "{{ check.name_then_code }}" is now <b>UP</b>.
+🟢 The check "{{ check.name_then_code }}" is now <b>UP</b>.
 {% endif %}