Add Pethost to Cloud Providers (#204)

Adds Pethost to Cloud Providers (alphabetical, between Linode and Sealos), as asked in gitea/docs#591 when the cloud providers moved here.

The link is Pethost's one-click Gitea template (`gitea/gitea:28-rootless`, SQLite; source: https://github.com/pethost-dev/templates/tree/main/gitea). It creates the administrator from the username, email and password given at deploy time, sets `DISABLE_REGISTRATION=true`, and serves Git over SSH on port 2222.

Guidelines checked: one link, sorted alphabetically, description on the same line ending with a period.

Reviewed-on: https://gitea.com/gitea/awesome-gitea/pulls/204
Reviewed-by: Lunny Xiao <[email protected]>
Co-authored-by: Stephan <[email protected]>

README.md

@@ -141,6 +141,7 @@ Zenith Hosting offers Gitea as a one-click deployment option on the platform. Th
 - [Cloudron](https://cloudron.io/button.html?app=io.gitea.cloudronapp) - 1-click Gitea install on Cloudron; the package is maintained at [git.cloudron.io](https://git.cloudron.io/cloudron/gitea-app).
 - [Exoscale](https://www.exoscale.com/marketplace/listing/glasskube-gitea/) - European cloud provider offering Gitea managed by Glasskube in its marketplace.
 - [Linode](https://www.linode.com/marketplace/apps/linode/gitea/) - Gitea is available as an app in the Linode Marketplace.
+- [Pethost](https://pethost.dev/templates/gitea/) - One-click Gitea template that creates the administrator at deploy time and closes registration.
 - [Sealos](https://sealos.io/products/app-store/gitea) - One-click Gitea deployment from the Sealos app store.
 
 ### Migration