fixed small bug in nearest neighbours function

app.py

@@ -21,7 +21,7 @@ if active_tab == "Nearest neighbours":
     
     with st.container():
         with col1:
-            word = st.multiselect("Enter a word", all_words)
+            word = st.multiselect("Enter a word", all_words, max_selections=1)[0]
             
         with col2:
             time_slice = st.selectbox("Time slice", ["Archaic", "Classical", "Hellenistic", "Early Roman", "Late Roman"])