Update create-ceramic-app.mdx

Author: JustinaPetr

docs/composedb/create-ceramic-app.mdx

@@ -11,6 +11,35 @@ Get up and running quickly with a basic ComposeDB application with one command.
 - **Node.js v20** - If you are using a different version, please use `nvm` to install Node.js v20 for best results.
 - **npm v10** - Installed automatically with NodeJS v20
 
+You will also need to run a ceramic-one node in the background which provides Ceramic 
+data network access. To set it up, follow the steps below:
+
+:::note
+The instructions below cover the steps for the MacOS-based systems. If you are running on a Linux-based system, you can find the 
+instructions [here](https://github.com/ceramicnetwork/rust-ceramic?tab=readme-ov-file#linux---debian-based-distributions).
+:::
+
+1. Install the component using [Homebrew](https://brew.sh/):
+
+```bash
+brew install ceramicnetwork/tap/ceramic-one
+```
+
+2. Start the `ceramic-one` using the following command:
+```bash
+ceramic-one daemon --network in-memory
+```
+
+:::note
+By default, the command above will spin off a node which connects to a `in-memory`. You can change this behaviour by providing a `--network` flag and specifying a network of your choice. For example:
+
+```ceramic-one daemon --network testnet-clay```
+:::
+
+---
+
+## Start the ComposeDB example app
+
 You can easily create a simple ComposeDB starter project by using our CLI and running the following command:
 
 <Tabs