Update README.md (#9379)

<!-- Clearly explain the need for these changes: -->

### Changes 🏗️

update backend readme to be more clear on where to run docker

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### Checklist 📋

#### For code changes:
- [ x] I have clearly listed my changes in the PR description
- [ ] I have made a test plan
- [ ] I have tested my changes according to the test plan:
  <!-- Put your test plan here: -->
  - [ ] ...

<details>
  <summary>Example test plan</summary>
  
  - [ ] Create from scratch and execute an agent with at least 3 blocks
- [ ] Import an agent from file upload, and confirm it executes
correctly
  - [ ] Upload agent to marketplace
- [ ] Import an agent from marketplace and confirm it executes correctly
  - [ ] Edit an agent from monitor, and confirm it executes correctly
</details>

#### For configuration changes:
- [ ] `.env.example` is updated or already compatible with my changes
- [ ] `docker-compose.yml` is updated or already compatible with my
changes
- [ ] I have included a list of my configuration changes in the PR
description (under **Changes**)

<details>
  <summary>Examples of configuration changes</summary>

  - Changing ports
  - Adding new services that need to communicate with each other
  - Secrets or environment variable changes
  - New or infrastructure changes such as databases
</details>

autogpt_platform/backend/README.md

@@ -66,10 +66,17 @@ We use the Poetry to manage the dependencies. To set up the project, follow thes
 
 ### Starting the server without Docker
 
+To run the server locally, start in the autogpt_platform folder:
+
+```sh
+cd ..
+```
+
 Run the following command to run database in docker but the application locally:
 
 ```sh
 docker compose --profile local up deps --build --detach
+cd backend
 poetry run app
 ```