simple shell script to quickly add aliases to zshrc (or similar) file

the following are also included in comments in the code for ease of reference:

1. rcfile - change to wherever you store your aliases (default: ~/.zshrc)

   • nb: do not enclose path with quotation marks

2. how/where to add to alias file - simply uncomment the preferred method (default: first line of file)

   • opt1: end of file
   • opt2: beginning of file (default)
   • opt3: at specific line of file (particularly useful if your file begins/ends with some control code)
     • nb: must change # to the appropriate line number: e.g., 3