title: replacing tabs with commas for multiple files
body: <p>How can I change .txt files, separated by tab, into csv files, separated by commas, without harming the format?</p>
  
  <p>I only managed to change the type from txt to csv but all data that was separated by tab, was placed in the same Excel cell.</p>
  
  <p>So what I'm asking here is:</p>
  
  <p>how to change tab to a comma for many files?
  how to then change the files from .txt to .csv?</p>