add unique_name.rst (#871)

doc/fluid/api/gen_doc.sh

 #!/bin/bash
 python gen_doc.py layers --submodules control_flow device io nn ops tensor learning_rate_scheduler detection metric_op > layers.rst
 
-for module in data_feeder dataset clip metrics executor initializer io nets optimizer profiler regularizer transpiler recordio_writer backward average profiler
+for module in data_feeder dataset clip metrics executor initializer io nets optimizer profiler regularizer transpiler recordio_writer backward average profiler unique_name
 do
   python gen_doc.py ${module} > ${module}.rst
 done

doc/fluid/api/index_en.rst

@@ -24,6 +24,7 @@ API Reference
     recordio_writer.rst
     regularizer.rst
     transpiler.rst
+    unique_name.rst
     data/dataset.rst
     data/data_reader.rst
 

doc/fluid/api/unique_name.rst

+..  THIS FILE IS GENERATED BY `gen_doc.{py|sh}`
+    !DO NOT EDIT THIS FILE MANUALLY!
+
+=================
+fluid.unique_name
+=================
+
+.. _api_fluid_unique_name_generate:
+
+generate
+--------
+
+..  autofunction:: paddle.fluid.unique_name.generate
+    :noindex:
+
+.. _api_fluid_unique_name_guard:
+
+guard
+-----
+
+..  autofunction:: paddle.fluid.unique_name.guard
+    :noindex:
+
+.. _api_fluid_unique_name_switch:
+
+switch
+------
+
+..  autofunction:: paddle.fluid.unique_name.switch
+    :noindex:
+