docs: moving documentation around to be more clear and easier to browse (#236)

* moving documentation around to be more clear and easier to browse

- moved assets into their own directory and updated links to them
- moved operating docs into their own directory
- consolidated kubernetes docs
- added docker-swarm folder for docs
- updated docs layout in docs/README.md to reflect the changes and make it easier to read

* docs: s/Operating Functions/Operating IronFunctions/

* docs: removing duplicate database link

* docs: moving databases into general docs

* docs: moving databases/mqs back

* docs: removing memory.md (duplicate of operating/routes.md)

* docs: converting to markdown bullets

docs/operating/docker.md

@@ -0,0 +1,21 @@
+# Docker Configuration
+
+To get the best performance, you'll want to ensure that Docker is configured properly. These are the environments known to produce the best results:
+
+1. Linux 4.7 or newer with aufs or overlay2 module.
+2. Ubuntu 16.04 LTS or newer with aufs or overlay2 module.
+3. Docker 1.12 or newer to be available.
+
+It is important to reconfigure host's Docker with this filesystem module. Thus, in your Docker start scripts you must do as following:
+
+```
+docker daemon [...] --storage-driver=overlay2
+```
+
+In case you are using Ubuntu, you can reconfigure Docker easily by updating `/etc/docker/daemon.json` and restarting Docker:
+
+```json
+{
+    "storage-driver": "overlay2"
+}
+```