title: C# cycle through random letters until a word is spelled
body: <p>Ok so I want to know how I would do this in a C# console application.</p>
  
  <p>Basically, I want to be able to generate a string with random letters, in a loop I want each character of the string to be replaced with another random character until a word is spelled. For example:</p>
  
  <p>asdfjnb  (initial string)
  soifnec
  tsdkjyk
  teiuhft  (random strings being generated, keeping the correct letters once generated)
  tesgneg
  testdha
  testifd
  testing  (final string)</p>