Support new editor scheme key for runtime errors (#131)

In JetBrains/intellij-community@6fb72d0,
the new `RUNTIME_ERROR` editor scheme key was added to the IDE platform
code to highlight runtime errors.

The new key has been added using `nord11` as foreground color.

Related to GH-120
Closes GH-127

resources/themes/nord.xml

@@ -3930,6 +3930,13 @@
         <option name="FOREGROUND" value="88c0d0" />
       </value>
     </option>
+    <option name="RUNTIME_ERROR">
+      <value>
+        <option name="FOREGROUND" value="ebcb8b" />
+        <option name="EFFECT_COLOR" value="bf616a" />
+        <option name="EFFECT_TYPE" value="5" />
+      </value>
+    </option>
     <option name="SASS_ATTRIBUTE_NAME">
       <value>
         <option name="FOREGROUND" value="81a1c1" />