Update Cloud Install section to recommend one-line installer

- Keep DigitalOcean referral link ($100 credit)
- Simplify instructions to 3 steps: create droplet, SSH, run installer
- Move one-line installation section into Cloud Install
- Add security reminder to change password and configure SSL
- Retain link to wiki for manual installation options
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f