Add Rust support

Refs pmd/pmd#5414

Author: adangel

_includes/about.html

@@ -20,7 +20,7 @@ <h2>About PMD</h2>
                 <p>
                     Additionally, it includes <strong>CPD</strong>, the copy-paste-detector. CPD finds duplicated code in
                     Coco, C/C++, C#, Dart, Fortran, Gherkin, Go, Groovy, HTML, Java, JavaScript, JSP, Julia, Kotlin,
-                    Lua, Matlab, Modelica, Objective-C, Perl, PHP, PLSQL, Python, Ruby, Salesforce.com Apex and
+                    Lua, Matlab, Modelica, Objective-C, Perl, PHP, PLSQL, Python, Ruby, Rust, Salesforce.com Apex and
                     Visualforce, Scala, Swift, T-SQL, Typescript, Apache Velocity, WSDL, XML and XSL.
                 </p>
                 <br/>