Fix rustfmt issues in CI jobs (#192)

Add .editorconfig file and fix rustfmt issues

.editorconfig

@@ -0,0 +1,5 @@
+# see https://editorconfig.org for more options, and setup instructions for yours editor
+
+[*.rs]
+indent_style = space
+indent_size = 4

src/tags.rs

@@ -42,8 +42,7 @@ fn untagged<T>(value: T) -> Tagged<T> {
 
 macro_rules! delegate {
     ($name: ident, $type: ty) => {
-        fn $name<E: serde::de::Error>(self, v: $type) -> Result<Self::Value, E>
-        {
+        fn $name<E: serde::de::Error>(self, v: $type) -> Result<Self::Value, E> {
             T::deserialize(v.into_deserializer()).map(untagged)
         }
     };