chore: remove closed issue documentation files

Removed 3 closed issue documentation files from docs/issues/:
- #34: epic-create-environment-command
- #51: subissue-9-fix-destroy-command-working-dir-support
- #52: subissue-10-document-create-environment-command

All these issues have been closed on GitHub and no longer need
local documentation files.

Remaining open issues: #16, #17, #18, #19

Author: josecelano