Revise Introduction to the Command Line

[nick-ulle]

As the title says, so that the topic order is:

• Getting Started with the Command Line
  • Keep the "Interacting with Computers" section
  • Introduce fewer shell commands right off the bat so learners don't feel overwhelmed; start with echo
• What Is a File System?
  • Overview of what file systems and paths are
• Navigating File Systems
  • Putting the previous section into practice with commands like pwd, ls, file, head, cat, cd
• Moving & Removing Files
  • Commands like mkdir, rmdir, cp, mv, rm
• Editing Files
  • All about text editors

More details are in the Google Sheet.

Also part of this issue is making sure that the old Intro to Command Line reader gets a note redirecting to this reader and that repository gets archived.