title: replace a word in a text file with the entire content of another file - sed
body: <p>I regularly use sed to replace words in text files with a variable or another word but what I would like to do is replace a place holder with the content of another file.</p>
  
  <p>In essence merging two documents together at a specific point in the target file.</p>
  
  <p>It would be easy if i just had to append the text to the bottom of the file but the text I wish to insert is right in the middle.</p>