refactor(swap): rename imported .md files to md- prefix for swap mechanism

Restore the canary file naming convention that swap_sources.py expects:
the imported MyST pages now live as docs/<dir>/md-<name>.md alongside
the existing docs/<dir>/<name>.rst, so swap_sources.py --swap can rename
them into place at build time.

- 254 .md files renamed (every page with a matching .rst counterpart)
- 2 MyST-only pages left at their final names (no .rst exists, no swap
  needed): docs/copyright.md, docs/automation/terraform/terraformvyos.md

All 114 stems listed in docs/_swap.txt now have a corresponding
md-<name>.md source file ready to swap in.

🤖 Generated by [robots](https://vyos.io)

1 files changed, 72 insertions, 0 deletions

diff --git a/docs/installation/virtual/md-docker.md b/docs/installation/virtual/md-docker.md
new file mode 100644
index 00000000..3489b94a
--- /dev/null
+++ b/docs/installation/virtual/md-docker.md
@@ -0,0 +1,72 @@
+---
+lastproofread: '2026-02-02'
+---
+
+(docker)=
+
+# Run VyOS in a Docker Container
+
+Docker is an open-source project for deploying applications as standardized
+units called containers. Deploying VyOS in a container provides a simple and
+lightweight mechanism for both testing and packet routing for container
+workloads.
+
+## IPv6 support for Docker
+
+VyOS requires an IPv6-enabled Docker network. Currently Linux distributions
+do not enable Docker IPv6 support by default. You can enable IPv6 support in
+two ways.
+
+### Method 1: Create a docker network with IPv6 support
+
+Here's an example using the `macvlan` driver.
+
+```none
+docker network create --ipv6 -d macvlan -o parent=eth0 --subnet 2001:db8::/64 --subnet 192.0.2.0/24 mynet
+```
+
+
+### Method 2: Add IPv6 support to the Docker daemon
+
+Edit /etc/docker/daemon.json to set the `ipv6` key to `true` and specify
+the `fixed-cidr-v6` to your desired IPv6 subnet.
+
+```none
+{
+  "ipv6": true,
+  "fixed-cidr-v6": "2001:db8::/64"
+}
+```
+
+Reload the Docker configuration.
+
+```none
+$ sudo systemctl reload docker
+```
+
+
+## Deploy container from ISO
+
+Download the ISO you want to base the container on. In this example,
+the ISO is `vyos-1.4-rolling-202308240020-amd64.iso`. If you
+created a custom IPv6-enabled network, include it as the `--net` parameter
+to `docker run`.
+
+```none
+$ mkdir vyos && cd vyos
+$ curl -o vyos-1.4-rolling-202308240020-amd64.iso https://github.com/vyos/vyos-rolling-nightly-builds/releases/download/1.4-rolling-202308240020/vyos-1.4-rolling-202308240020-amd64.iso
+$ mkdir rootfs
+$ sudo mount -o loop vyos-1.4-rolling-202308240020-amd64.iso rootfs
+$ sudo apt-get install -y squashfs-tools
+$ mkdir unsquashfs
+$ sudo unsquashfs -f -d unsquashfs/ rootfs/live/filesystem.squashfs
+$ sudo tar -C unsquashfs -c . | docker import - vyos:1.4-rolling-202111281249
+$ sudo umount rootfs
+$ cd ..
+$ sudo rm -rf vyos
+$ docker run -d --rm --name vyos --privileged -v /lib/modules:/lib/modules \
+> vyos:1.4-rolling-202111281249 /sbin/init
+$ docker exec -ti vyos su - vyos
+```
+
+To stop the container, run `docker stop vyos`.