CONTRIBUTING.md: Docker for Windows requirements

Docker Desktop for Window requires Windows 10 64-bit,
"Professional" or "Enterprise" editions.

CONTRIBUTING.md

@@ -6,10 +6,10 @@
 https://help.github.com/articles/fork-a-repo/
 
 ### 2 Install Docker.
-- **Windows 10:** https://store.docker.com/editions/community/docker-ce-desktop-windows
+- **Windows 10 (Pro/Enterprise, 64-bit):** https://store.docker.com/editions/community/docker-ce-desktop-windows
 - **macOS El Capitan 10.11 and newer:** https://store.docker.com/editions/community/docker-ce-desktop-mac
 
-_(Older Mac or Windows PC? See [instructions for Docker Toolbox](https://github.com/RefugeRestrooms/refugerestrooms/wiki/How-to-use-Docker-Toolbox-with-Refuge-Restrooms).)_
+_(Other Mac or Windows OS? See [instructions for Docker Toolbox](https://github.com/RefugeRestrooms/refugerestrooms/wiki/How-to-use-Docker-Toolbox-with-Refuge-Restrooms).)_
 
 _(Running Linux? See [instructions for Docker CE on Linux](https://github.com/RefugeRestrooms/refugerestrooms/wiki/How-to-use-Docker-CE-on-Linux-with-Refuge-Restrooms).)_