Add information to "FAQ/Guidelines" re: alternative illegal content reporting channel

This information will allow illegal content to be reported by those who don't have an Arduino Forum account.

Author: per1234

content/categories/staff/_topics/faq-guidelines/1.md

@@ -49,6 +49,16 @@ When you see bad behavior, don’t reply. It encourages the bad behavior by ackn
 
 In order to maintain our community, moderators reserve the right to remove any content and any user account for any reason at any time. Moderators do not preview new posts; the moderators and site operators take no responsibility for any content posted by the community.
 
+<a name="illegal-content"></a>
+
+### [Illegal Content](#illegal-content)
+
+If you see illegal content on **Arduino Forum**, [flag](https://meta.discourse.org/t/flag-a-post-for-moderator-attention/32783) the post and select "**It's Illegal**" from the list of reasons for flagging in the dialog that appears.
+
+If you don't have an **Arduino Forum** account, you can report illegal content here:
+
+https://report-content.arduino.cc/
+
 <a name="be-civil"></a>
 
 ## [Always Be Civil](#be-civil)