add .editorconfig

Signed-off-by: alexferl <me@alexferl.com>

Author: alexferl

.editorconfig

@@ -0,0 +1,17 @@
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+trim_trailing_whitespace = true
+indent_style = space
+indent_size = 2
+
+[{Makefile,go.mod,go.sum,*.go}]
+indent_style = tab
+indent_size = 4
+
+[*.md]
+indent_size = 4
+trim_trailing_whitespace = false