Add /about command

[Vulp35]

About the bot

• Authors
  • Russ, KF0JOU
• Tools
  • Node.js
  • Discord.js
• Data Sources (this is what the current python bot uses)
  • Solar conditions from hamqsl.com
  • Online callsign lookups from HamQTH and callook.info
  • Maximum Usable Frequency (MUF) data from prop.kc2g.com
• Uptime (might keep?)
• Version and Credits
  • HamHero 1.2.0 by KF0JOU.
  • Based on HamTheMan by thisguyistotallybent
  • HamBot by N4OG