add "how-to" guide for subscribing to newsletter

content/pages/about.en.md

@@ -35,6 +35,13 @@ Have a look at the [accessibility outline](/en/pages/accessibility.html) of the
 
 You can subscribe to our [mailing list](https://we.lurk.org/postorius/lists/varia.we.lurk.org/) to be kept up to date with what's going on.
 
+If you wish to subscribe to the newsletter, you can follow the steps below:
+    1. Visit this link: https://we.lurk.org/mailman3/lists/varia.we.lurk.org/
+    2. Under the "Subscription / Unsubscription" heading, fill in your email address and optionally, your name and then click the "subscribe" button.
+    3. You will be sent an email to the address you filled in during the previous step (this can take some time and please check your spam inbox)
+    4. You can confirm your subscription by responding to this email (an empty message will suffice).
+    5. Enjoy the Varia newsletter!
+
 # Chat
 
 Some of us lurk [#varia](https://webchat.freenode.net/?channel=#varia) on the IRC Freenode network.