mention bind-propagation and add link to hotio

README.md

@@ -1,6 +1,6 @@
 % mergerfs(1) mergerfs user manual
 % Antonio SJ Musumeci <trapexit@spawn.link>
-% 2021-02-08
+% 2021-05-29
 
 # NAME
 
@@ -1143,6 +1143,8 @@ Yes. With Docker you'll need to include `--cap-add=SYS_ADMIN --device=/dev/fuse
 
 Keep in mind that you **MUST** consider identity when using containers. For example: supplemental groups will be picked up from the container unless you properly manage users and groups by sharing relevant /etc files or by using some other means to share identity across containers. Similarly if you use "rootless" containers and user namespaces to do uid/gid translations you **MUST** consider that while managing shared files.
 
+Also, as mentioned by [hotio](https://hotio.dev/containers/mergerfs), with Docker you should probably be mounting with `bind-propagation` set to `slave`.
+
 
 #### Does mergerfs support CoW / copy-on-write / writes to read-only filesystems?