added editorconfig (#2403)

* style minor fixes

* added editorconfig

* updated editorconfig

.editorconfig

+root = true
+
+[*]
+charset=utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+indent_style = space
+indent_size = 2
+
+[*.{py,sh,js}]
+indent_size = 4
+
+# Placeholder files
+[{*.gitkeep,__init__.py}]
+insert_final_newline = none
+
+# Tabs matter for Makefile and .gitmodules
+[{makefile*,Makefile*,*.mk,*.mak,*.makefile,*.Makefile,GNUmakefile,BSDmakefile,make.bat,Makevars*,*.gitmodules}]
+indent_style = tab

LICENSE

 The MIT License (MIT)
 
-Copyright (c) Microsoft Corporation 
+Copyright (c) Microsoft Corporation
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -19,4 +19,3 @@ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
-

R-package/LICENSE

 The MIT License (MIT)
 
-Copyright (c) Microsoft Corporation 
+Copyright (c) Microsoft Corporation
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -19,4 +19,3 @@ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
-

docs/Parameters.rst

@@ -264,7 +264,7 @@ Learning Control Parameters
 
 -  ``feature_fraction_bynode`` :raw-html:`<a id="feature_fraction_bynode" title="Permalink to this parameter" href="#feature_fraction_bynode">&#x1F517;&#xFE0E;</a>`, default = ``1.0``, type = double, aliases: ``sub_feature_bynode``, ``colsample_bynode``, constraints: ``0.0 < feature_fraction_bynode <= 1.0``
 
-   -  LightGBM will randomly select part of features on each tree node if ``feature_fraction_bynode`` smaller than ``1.0``. For example, if you set it to ``0.8``, LightGBM will select 80% of features at each tree node.
+   -  LightGBM will randomly select part of features on each tree node if ``feature_fraction_bynode`` smaller than ``1.0``. For example, if you set it to ``0.8``, LightGBM will select 80% of features at each tree node
 
    -  can be used to deal with over-fitting
 

include/LightGBM/config.h

@@ -279,7 +279,7 @@ struct Config {
   // alias = sub_feature_bynode, colsample_bynode
   // check = >0.0
   // check = <=1.0
-  // desc = LightGBM will randomly select part of features on each tree node if ``feature_fraction_bynode`` smaller than ``1.0``. For example, if you set it to ``0.8``, LightGBM will select 80% of features at each tree node.
+  // desc = LightGBM will randomly select part of features on each tree node if ``feature_fraction_bynode`` smaller than ``1.0``. For example, if you set it to ``0.8``, LightGBM will select 80% of features at each tree node
   // desc = can be used to deal with over-fitting
   // desc = **Note**: unlike ``feature_fraction``, this cannot speed up training
   // desc = **Note**: if both ``feature_fraction`` and ``feature_fraction_bynode`` are smaller than ``1.0``, the final fraction of each node is ``feature_fraction * feature_fraction_bynode``