[docs] fixed typos (#1211)

* fixed typo

* fixed render of default value of metric param

* fixed typos

docs/Parameters.rst

@@ -576,7 +576,7 @@ Objective Parameters
 Metric Parameters
 -----------------
 
--  ``metric``, default=``None``, type=multi-enum
+-  ``metric``, default=\ ``None``, type=multi-enum
 
    -  if ``None``, metric corresponding to specified application will be used
 
@@ -720,7 +720,7 @@ In this case LightGBM will auto load initial score file if it exists.
 Weight Data
 ~~~~~~~~~~~
 
-LightGBM supporta weighted training. It uses an additional file to store weight data, like the following:
+LightGBM supports weighted training. It uses an additional file to store weight data, like the following:
 
 ::
 
@@ -741,7 +741,7 @@ Query Data
 ~~~~~~~~~~
 
 For LambdaRank learning, it needs query information for training data.
-LightGBM use an additional file to store query data, like the following:
+LightGBM uses an additional file to store query data, like the following:
 
 ::