add EditorConfig

.editorconfig

@@ -0,0 +1,27 @@
+# EditorConfig is awesome: https://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+end_of_line = lf
+insert_final_newline = true
+
+# Matches multiple files with brace expansion notation
+# Set default charset
+[*]
+charset = utf-8
+
+# 4 space indentation
+[*.cs]
+indent_style = space
+indent_size = 4
+
+# Tab indentation (no size specified)
+[Makefile]
+indent_style = tab
+
+[*.{js,json,xaml,axaml}]
+indent_style = space
+indent_size = 2