docs: add documentation regarding --no-dns flag (#93)

docs/docs/2-getting-started/2-deploy-demo-app.md

@@ -271,6 +271,14 @@ Want to use your own domain, for example, `excalidraw.example.com` instead of `e
 Add a CNAME record `excalidraw.example.com` in your DNS provider (Cloudflare, Namecheap, etc.) pointing to
 `excalidraw.7za6s7.cluster.uncloud.run`. Alternatively, you can add an A record pointing to your server's IP.
 
+:::info note
+
+These instructions set up your own domain _in addition to_ uncloud's managed DNS service.
+
+If you want to avoid the managed service altogether, add `--no-dns` to your `uc machine init` command, and point an `A`-type DNS record to your server(s)'s IP(s).
+
+:::
+
 Then update the published port `80/https` in `compose.yaml` to use your domain:
 
 ```yaml title="compose.yaml"
@@ -297,8 +305,8 @@ Choose [y/N]: y
 Chose: Yes!
 
 [+] Deploying services 2/2
- ✔ Container excalidraw-0z12 on machine-dc3c  Started                       3.5s 
- ✔ Container excalidraw-azpc on machine-dc3c  Removed                       3.4s 
+ ✔ Container excalidraw-0z12 on machine-dc3c  Started                       3.5s
+ ✔ Container excalidraw-azpc on machine-dc3c  Removed                       3.4s
 ```
 
 Notice how Uncloud performed a **zero-downtime deployment** — it started the new container with the updated

docs/user_guide.md

@@ -20,7 +20,7 @@ Uncloud stores its configuration in `~/.config/uncloud/config.yaml`. If you wish
 
 ### Initialisation
 
-Begin by initialising the first node in your cluster with `uc machine init [USER@HOST:PORT]`. If you do not have a need for Caddy reverse proxy, you may disable this feature with `--no-caddy`.
+Begin by initialising the first node in your cluster with `uc machine init [USER@HOST:PORT]`. If you do not have a need for Caddy reverse proxy, you may disable this feature with `--no-caddy`. If you want to avoid using uncloud's managed DNS service, add the `--no-dns` flag.
 
 This command will idempotently install Docker, uncloudd, uncloud-corrosion. If Caddy is enabled, it will set up a reverse proxy. If Uncloud DNS is enabled, it will create a DNS A record for the machine's public IP address under `*.[CLUSTER ID].cluster.uncloud.run`.
 
@@ -37,6 +37,7 @@ Uncloud (uncloud.run) DNS can be managed with the `uc dns` subcommand.
 * To reserve a domain name, run `uc dns reserve`
 * To release a domain name, run `uc dns release`.
 * To see the domain name, run `uc dns show`
+* To avoid using the Uncloud managed DNS service, use the `--no-dns` flag on your `uc machine init` command.
 
 ### Running a service