Add guide.md
Add guide.md

iwayvietnam/openpgp-secure-zimlet,nguyennv/openpgp-zimlet,iwayvietnam/openpgp-secure-zimlet,iwayvietnam/openpgp-secure-zimlet,nguyennv/openpgp-zimlet,nguyennv/openpgp-zimlet,nguyennv/openpgp-secure-zimlet,nguyennv/openpgp-secure-zimlet,nguyennv/openpgp-secure-zimlet