docs: Add enterprise docs for preset orgs.

docs/Enterprise.md

@@ -0,0 +1,27 @@
+# Configuring Zulip Desktop for multiple users
+
+If you're a system admin and want to add certain organizations to the Zulip app for
+all users of your system, you can do so by creating an enterprise config file.
+The file should be placed at `/etc/zulip-desktop-config` for Linux and macOS computers
+and inside `C:\Program Files\Zulip-Desktop-Config` on Windows.
+It must be named `global_config.json` in both cases. 
+
+To specify the preset organization you want to add for other users, you will need to
+add the `json` shown below to the `global_config.json`. Replace `https://chat.zulip.org` with the
+organization you want to add. You can also specify multiple organizations. 
+
+```json
+{
+	"presetOrganizations": ["https://chat.zulip.org"],
+	"autoUpdate": true
+}
+```
+
+The above example adds [Zulip Community](https://chat.zulip.org) to Zulip every time the app is loaded. 
+Users can add new organizations at all times, but cannot remove any organizations listed under `presetOrganizations`.
+
+If you'd like to remove organizations and have admin access, you'll need to change the config file and remove the concerned URL from the `value` field.
+
+It also turns on automatic updates for every Zulip user on the same machine. 
+
+> Currently, we only support `presetOrganizations` and `autoUpdate` settings. We are working on other settings as well, and will update this page when we add support for more.