chore: add editorconfig

- editorconfig is de facto a standard to define consistent style across
  various file formats and developers

Signed-off-by: AtomicFS <vojtech.vesely@9elements.com>

Author: AtomicFS

.editorconfig

@@ -0,0 +1,20 @@
+# EditorConfig: https://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+end_of_line = lf
+charset = utf-8
+indent_style = tab
+
+[*.{json,yml,yaml,proto}]
+indent_style = space
+indent_size = 2
+
+[{*.md,LICENSE}]
+indent_style = unset
+indent_size = unset
+generated_code = true
+