Fix typos <noupdate>

src/year2/natural-language-processing/sections/_rnn.tex

@@ -207,7 +207,7 @@
                 Provide an initial hidden state to the RNN (e.g., speech-to-text).
         \end{description}
 
-    \item[Sequence labelling] \marginnote{Sequence labelling}
+    \item[Sequence labeling] \marginnote{Sequence labeling}
         Assign a class to each input token (e.g., POS-tagging, named-entity recognition, structure prediction, \dots).
 
     \item[Sequence classification] \marginnote{Sequence classification}