Docker issue: /ipfs and /ipns are empty within container despite node having pinned files

I'm not sure if there's a bug with the Docker setup in the README, or if there are missing steps that should be documented.

Despite having a test file uploaded and pinned in my IPFS web dashboard, and the daemon set to mount them automatically, the folders in `/ipns` (and `/ipfs`) are empty within Docker and do not contain my test data.

If I try to mount them as volumes on the host, not only are they empty but they don't even contain the empty `12D3K...` and `local` dirs that were visible from within the container.


I have the following `docker-compose.yml` setup as instructed by the README and this document: https://github.com/ipfs/go-ipfs/blob/master/docs/fuse.md#mounting-ipfs:
```yml
version: '2.4'

services:
ipfs:
image: ipfs/go-ipfs:latest
command: daemon --migrate=true --mount
#privileged: true # not needed in theory, adding this makes no difference though
cap_add:
- SYS_ADMIN
security_opt:
- apparmor:unconfined
devices:
- /dev/fuse:/dev/fuse
ports:
- 8080:8080 # public gateway
- 4001:4001 # public swarm UDP
- 5001:5001 # private API
volumes:
- /etc/fuse.conf:/etc/fuse.conf:ro
- ./data/ipfs:/data/ipfs
- ./data/export:/export
#- ./data/shares/ipfs:/ipfs # eventually want to do this, but baby steps first
#- ./data/shares/ipns:/ipns
```
`/etc/fuse.conf`:
```
user_allow_other
```
`/data/ipfs/config`:
```
...
"Mounts": {
"FuseAllowOther": true,
"IPFS": "/ipfs",
"IPNS": "/ipns"
},
```

When I start the container with `docker-compose up` it reports that `/ipfs` and `/ipns` have been successfully mounted, but they remain empty within the container despite having pinned files.
```logs
$ docker-compose up
Creating network "zerviceipfs_default" with the default driver
Creating zerviceipfs_ipfs_1 ... done
Attaching to zerviceipfs_ipfs_1
ipfs_1 | Changing user to ipfs
ipfs_1 | ipfs version 0.8.0-rc2
ipfs_1 | Found IPFS fs-repo at /data/ipfs
ipfs_1 | Initializing daemon...
ipfs_1 | go-ipfs version: 0.8.0-rc2-4080333
ipfs_1 | Repo version: 11
ipfs_1 | System version: amd64/linux
ipfs_1 | Golang version: go1.14.4
ipfs_1 | 2021/02/17 19:50:48 failed to sufficiently increase receive buffer size (was: 208 kiB, wanted: 2048 kiB, got: 416 kiB). See https://github.com/lucas-clemente/quic-go/wiki/UDP-Receive-Buffer-Size for details.
ipfs_1 | Swarm listening on /ip4/127.0.0.1/tcp/4001
...
ipfs_1 | Swarm announcing /ip4/76.71.247.47/tcp/4001
ipfs_1 | API server listening on /ip4/0.0.0.0/tcp/5001
ipfs_1 | WebUI: http://0.0.0.0:5001/webui
ipfs_1 | IPFS mounted at: /ipfs
ipfs_1 | IPNS mounted at: /ipns
ipfs_1 | Gateway (readonly) server listening on /ip4/0.0.0.0/tcp/8080
ipfs_1 | Daemon is ready
```
```bash
$ docker-compose exec --user=root ipfs /bin/sh
/ # whoami
root
/ # ls /ip*s/**
/ipns/12D3KooWCSPrazUW7QNcpvWJh3jaWzErz52SrKC9X6uXqB4XVp4c:

/ipns/local:
/ #
```

I'm trying to eventually mount `/ipfs` and `/ipns` as volumes so that the host OS can write files into them, but I cant even get them working within the container as regular non-volume folders first. The eventually goal is to be able to put a folder into `~/myfiles` on the host, and have it automatically uploaded by `ipfs` within the docker container without having to mess around with the `ipfs files` cli to `add` files manually.

Not sure if this ticket means that isn't possible yet: https://github.com/ipfs/roadmap/issues/90 If it's definitely not possible then that should probably also be documented in the README so people don't waste time trying to get mounts working from within Docker. However *this* issue is specific to the fact that `/ipfs` and `/ipns` are empty when they should contain data.

Semi-related issues:
- https://github.com/ipfs/roadmap/issues/90
- https://github.com/ipfs-shipyard/ipfs-desktop/issues/618
- https://github.com/ipfs/go-ipfs/issues/6542
- https://discuss.ipfs.io/t/mounting-ipfs-or-ipns-as-read-write-directory/5970/3
- https://github.com/ipfs-inactive/package-managers/issues/74#issuecomment-576777391
- https://github.com/ipfs-inactive/package-managers/issues/71
- https://github.com/jfmherokiller/ipfs-mfs-fuse
- https://github.com/piedar/js-ipfs-mount