Remove some issues:

- https://github.com/mathml-refresh/mathml/issues/139 is moved to level 2
- MathMLElement includes ElementCSSInlineStyle should be reported to CSSWG

index.html

@@ -838,15 +838,10 @@ <h4>DOM and Javascript</h4>
                  data-include-format="text"></pre>
             <img src="examples/example-dom-idl.png" alt="dom-idl example"/>
           </div>
-          <div class="issue" data-number="139">Specialize <a>unknown MathML elements</a> to a <code>MathMLUnknownElement</code> interface?</div>
           <div class="issue">
             <a href="https://github.com/whatwg/html/pull/5248">Rename
               HTMLOrSVGElement</a> and define MathMLElement in [[HTML]].
           </div>
-          <div class="issue">
-            Move <code>HTMLElement includes ElementCSSInlineStyle;</code>
-            to the [[CSSOM]] specification.
-          </div>
         </section>
         <section id="text-layout">
           <h4>Text layout</h4>