Issue system

[sopyb]

Create a system for issues so that other users can point out errors in the roadmaps

• [x] Creating an issue
• [x] Getting issues
  • [x] Full issue details
  • [x] Issues on roadmap
• [x] Updating
  • [x] Title
  • [x] Content
  • [x] Opening and closing
• [x] Deleting issues
• [x] #21