add .editorconfig

.editorconfig

@@ -0,0 +1,19 @@
+###############################
+# Core EditorConfig Options   #
+###############################
+root = true
+
+# All files
+[*]
+indent_style = space
+charset = utf-8
+
+[*.{csproj,vbproj,vcxproj,vcxproj.filters,proj,projitems,shproj,props,targets,ruleset,config,nuspec,resx,vsixmanifest,vsct,proto,json}]
+indent_size = 2
+
+[*.cs]
+indent_size = 4
+
+# Wrapping preferences
+csharp_preserve_single_line_statements = true
+csharp_preserve_single_line_blocks = true