Add documentation on the morphoFeatures when updating the morphological features using Ssurgeon. Currently, there is no way to update features without wiping out the entire features map. This could be changed if needed

Author: AngledLuffa

src/edu/stanford/nlp/semgraph/semgrex/ssurgeon/Ssurgeon.java

@@ -133,6 +133,9 @@
  * {@code editNode} will edit the attributes of a word.
  * {@code -node} is the node to edit.
  * {@code ...attributes...} are the attributes to change, same as with {@code addDep}
+ *   {@code -morphofeatures ...} will set the features to be exactly as written.  TODO: if anyone
+ *   needs the ability to add or remove features without resetting the entire features map,
+ *   please file an issue on github.
  *</p><p>
  * {@code combineMWT} will add MWT attributes to a sequence of two or more words.
  * {@code -node} (repeated) is the nodes to edit.