code: function(docs) {
    return _.reject(docs, function (doc) {
      if (!!doc.external) {
        externalTypes[doc.name] = doc.see[0];
        return true;
      }
      return false;
    });
  }
docs: Filters out types with @external annotations and adds their @see link to the
  externalTypes table
  
  @param {Array.<Object>} docs The jsdoc list.