add a link so folks can sign up for the newsletter

Author: lheagy

Makefile

@@ -3,4 +3,4 @@ PORT=9080
 .PHONY: run
 
 run:
-	python -m SimpleHTTPServer $(PORT)
+	python -m http.server $(PORT)

index.html

@@ -154,6 +154,7 @@ <h2 id="contact">&#x1F4E2; Contacting Us &#x1F4E2;</h2>
         Please don't hesitate to reach out and ask a question! We love to hear about how people are using or want to use SimPEG!
         <p>
             <ul class="icons">
+                <li><i class="fas fa-envelope fa-lg"></i><a href="https://cdn.forms-content.sg-form.com/ed4ab287-df4b-11eb-88f6-421855200eee">Sign up for the newsletter</a></li>
                 <li><i class="fab fa-discourse fa-lg"></i>Join the community forum on <a href="https://simpeg.discourse.group">Discourse</a></li>
                 <li><i class="fab fa-slack fa-lg"></i>Send us a message on <a href="http://slack.simpeg.xyz">Slack</a></li>
                 <li><i class="fab fa-github fa-lg"></i>Contact us on <a href="https://github.com/simpeg">GitHub</a> by creating a <a href="https://github.com/simpeg/simpeg/issues/new">new issue</a></li>