docs: updated create-medusa-app steps (#4327)

docs/content/troubleshooting/create-medusa-app-errors/_eagain-error.md

@@ -0,0 +1,33 @@
+When using the `create-medusa-app` npx command, you might run into an NPM `EAGAIN` error. This error can randomly occur due to conflicting processes.
+
+The easiest solution is to start the command over. Alternatively, if your setup crossed the "create database" point, you can manually perform the following steps in the directory of your created project. You can skip any steps that you're sure have been performed by `create-medusa-app`:
+
+1\. Install dependencies:
+
+```bash npm2yarn
+npm install
+```
+
+2\. Build project:
+
+```bash npm2yarn
+npm run build
+```
+
+3\. Run migrations:
+
+```bash
+npx @medusajs/medusa-cli migrations run
+```
+
+4\. Optionally seed the database:
+
+```bash
+npx @medusajs/medusa-cli seed -f ./data/seed.json
+```
+
+5\. Start project:
+
+```bash
+npx @medusajs/medusa-cli develop
+```