title: C# adding a character in a string
body: <p>I know I can append to a string but I want to be able to add a specific character after every 5 characters within the string</p>
  
  <p>from this
  string alpha = abcdefghijklmnopqrstuvwxyz</p>
  
  <p>to this
  string alpha = abcde-fghij-klmno-pqrst-uvwxy-z</p>