[DOCS] remove "online" and "offline" title as "FTRL" can be use onlin…

…e or offline

README.md

@@ -70,12 +70,10 @@
 		* [Neural Factorization Machine(NFM)](./docs/algo/nfm_on_angel.md)
 		* [Product Neural Network(PNN)](./docs/algo/pnn_on_angel.md)
 * **Spark on Angel**
-	* **Online Learning**
-		* [FTRL](./docs/algo/ftrl_lr_spark.md)
-	* **Offline Learning**
-		* [Logistic Regression(LR)](./docs/algo/sona/lr_sona.md)
-		* [Word2Vec](./docs/algo/sona/word2vec_sona.md)
-		* [LINE](./docs/algo/sona/line_sona.md)
+	* [FTRL](./docs/algo/ftrl_lr_spark.md)
+	* [Logistic Regression(LR)](./docs/algo/sona/lr_sona.md)
+	* [Word2Vec](./docs/algo/sona/word2vec_sona.md)
+	* [LINE](./docs/algo/sona/line_sona.md)
 
 
 ## Deployment