doc typo: "classificaion" -> "classification"
doc typo: "classificaion" -> "classification"

Author: muxator <muxator@users.noreply.github.com>

Closes #10008 from muxator/patch-1.

(cherry picked from commit 4376b5bea8171e4e73b3dbabbfdf84fa1afd140b)
Signed-off-by: Reynold Xin <c9d35a384bc579d1c6c8c055f2a2b5c04e11b521@databricks.com>

haowu80s/spark,haowu80s/spark,haowu80s/spark,haowu80s/spark,haowu80s/spark,haowu80s/spark