feat: add an editorconfig for rust

.editorconfig

@@ -0,0 +1,29 @@
+# EditorConfig helps maintain consistent coding styles
+# across different editors and IDEs
+# https://editorconfig.org
+
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+trim_trailing_whitespace = true
+indent_style = space
+indent_size = 4
+
+[*.rs]
+indent_size = 4
+max_line_length = 100
+
+[*.toml]
+indent_size = 2
+
+[*.{yml,yaml}]
+indent_size = 2
+
+[*.md]
+trim_trailing_whitespace = false
+
+[Makefile]
+indent_style = tab