style: whitespaces and formatting fixed to make pre-commit happy

docs/index.md

@@ -19,14 +19,14 @@ The library source code is hosted on [GitHub](https://github.com/mpusz/mp-units)
     To achieve that, it extensively uses C++20 features and the
     [explicit object parameter](https://en.cppreference.com/w/cpp/language/member_functions#Explicit_object_parameter)
     from C++23.
-    
+
     Even though the library benefits from C++23 (if available), C++20 is enough to compile and
     use all of the library's functionality. C++23 features are hidden behind a preprocessor macro
     providing a backward-compatible way to use it.
-    
+
     Sadly, as of today, only a few compilers provide full C++20 support. The library compiles fine
     on the following compilers (or newer):
-    
+
     - gcc-12.2
 
     In the upcoming weeks, we will be actively working to extend the support to other compilers as well.