Update use of cronie script use

[kprosise]

added info about -k and did some minor changes to how "image name must be last arg" was worded.

Signed-off-by: Katrina Prosise igorina@toganlabs.com

repo: mion

• Issue: mion #140
• Rendered page viewed with: grip
• If instructional,
  • Affected hardware: n/a
  • Verified: Yes
• Description: Updated the info about cronie usage and arg order