Publicly document the C & C++ Language WG meetings

We've been hosting these meetings regularly for a while now, so this
begins advertising the meetings more widely.

clang/www/get_involved.html

@@ -39,6 +39,17 @@ <h2>Follow what's going on</h2>
 This forum is for everything else Clang related (questions and answers, design
 discussions, etc).</li>
 
+<li>Regular meetings are held on the
+<a href="https://drive.google.com/file/d/1S7V0MHP4xMs1yUQ9Gv9LHn5bwDfFVapn/view?usp=sharing">
+first and third Wednesday</a> of each month to discuss C and C++
+standards-related activities happening within the Clang community. These
+meetings are a way to coordinate efforts between implementers and provide
+updates on how standards activities are going. Meeting agendas and minutes are
+available
+<a href="https://docs.google.com/document/d/1x5-RbOC6-jnI_NcJ9Dp4pSmGhhNe7lUevuWUIB46TeM/edit?usp=sharing">
+here<a>.
+</li>
+
 </ul>
 
 <p>The most common way to talk with other developers on the project is through