Add an .editorconfig file

Some editors pick this file up to set default style options.

Change-Id: Ia043d0a3bd8730e3ec576e26e93fef7602fede56
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.sourcearcade.org/c/flashprog/+/62
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..eb44fcd
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,11 @@
+# EditorConfig: https://EditorConfig.org
+
+root = true
+
+[*]
+indent_style = tab
+tab_width = 8
+charset = utf-8
+insert_final_newline = true
+end_of_line = lf
+trim_trailing_whitespace = true