Fix MSRV & update changelog

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## 0.16.0
+
+### Enhancements
+
+* Added `slice_str` util.
+
 ## 0.15.8
 
 ### Enhancements

src/utils.rs

@@ -831,7 +831,7 @@ pub fn slice_str<'a>(s: &'a str, head: &str, bounds: Range<usize>, tail: &str) -
         if head.is_empty() && tail.is_empty() {
             Cow::Borrowed(slice)
         } else {
-            Cow::Owned(format!("{head}{slice}{tail}"))
+            Cow::Owned(format!("{}{}{}", head, slice, tail))
         }
     }
 }