Need to have image input from both command line and slash command that inserts the image into the message array for chatclient

[robch]

Requirements:

• this works: cycod --image FILE.png --input "describe what's in here"
• this works: cycod
  • user: /image FILE.png
  • ... assistant label ... : Added image file 'FILE.png'
  • user: describe what's in here
• cycod help find image => shows help topics
• cycod help options => shows that --image works w/ cycod
• cycod help image => shows that you can use --image and /image
• any other places that show all the slash commands, do so with this one
• examples for --image somewhere in cycod help topics as well
• at least one test for --image
• at least one test for /image
• README.md is updated for these changes
• --image and /image also support glob patterns to find images, and we'll attach multiple