docs(readme): name the container in the quick-start docker example

Self-hosted feedback: a user on Orange Pi 5B copied the README quick-
start `docker run` line and then couldn't find the container with
`docker logs` because the command didn't pass `--name`, so Docker
assigned a random adjective-noun name. Same friction as filing an
issue with no container id.

Aligns the quick-start with the detailed "Option A" block lower in
the README that already had --name velxio. Also points at
`docker logs -f velxio` so the next person knows how to tail without
hunting for the auto-generated name.

README.md

@@ -40,7 +40,9 @@ Your support helps cover server costs, library maintenance, and frees up time to
 To self-host with Docker (single command):
 
 ```bash
-docker run -d -p 3080:80 \
+docker run -d \
+  --name velxio \
+  -p 3080:80 \
   -v velxio-data:/app/data \
   -v velxio-arduino-libs:/root/.arduino15 \
   -v velxio-arduino-user-libs:/root/Arduino \
@@ -49,7 +51,8 @@ docker run -d -p 3080:80 \
   ghcr.io/davidmonterocrespo24/velxio:master
 ```
 
-Then open <http://localhost:3080>.
+Then open <http://localhost:3080>. Tail logs any time with
+`docker logs -f velxio`.
 
 The named volumes are what make compile times reasonable on subsequent
 runs — without them, every container restart wipes the ESP-IDF build