title: VSCode and clang-format: use my own file extension
body: <p>I use Visual Studio Code with clang-format extension to format .c source code files - it works.</p>
  
  <p>Now I have special files (C-style, also) but that files are not recognized for formatting since they have another file extension (.kki).</p>
  
  <p>How can I configure the clang-format extension within Visual Studio Code to recognize my <code>.kki</code> files as C-source code files?</p>