Plugin works also for TEI XML element formula

Plugin works for something like:

          <formula>\frac{x^2+y^2}{z}=1</formula>

Signed-off-by: Margareth Warburton <margareth.warburton@unibas.ch>

Author: MargarethWarburton

latex-images-support/wsAccess.js

@@ -7,6 +7,7 @@ function applicationStarted(pluginWorkspaceAccess) {
         },
         canHandleNodeContext: function (nodeContext) {
             return "latex" == nodeContext.getNodeName() 
+              || "formula" == nodeContext.getNodeName()
               || ("foreign" == nodeContext.getNodeName() && "embed-latex" == nodeContext.getAttributeValue("outputclass"))
               || ("tex-math" == nodeContext.getNodeName() && "LaTeX" == nodeContext.getAttributeValue("notation"));
         },