feat(ci): create formatter config

rustfmt.toml

@@ -0,0 +1,12 @@
+max_width = 100
+hard_tabs = false
+tab_spaces = 4
+newline_style = "Auto"
+use_small_heuristics = "Default"
+reorder_imports = true
+reorder_modules = true
+edition = "2021"
+use_try_shorthand = false
+use_field_init_shorthand = false
+force_explicit_abi = true
+merge_derives = true