chore: Server Setup Readme Update (#21291)

## Description
> Updated Server Setup Readme file to include Replica Set in the MongoDB setup command

Fixes #21290 


## Type of change

- Chore 

## Checklist:
### Dev activity
- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [x] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] PR is being merged under a feature flag


### QA activity:
- [ ] Test plan has been approved by relevant developers
- [ ] Test plan has been peer reviewed by QA
- [ ] Cypress test cases have been added and approved by either SDET or manual QA
- [ ] Organized project review call with relevant stakeholders after Round 1/2 of QA
- [ ] Added Test Plan Approved label after reveiwing all Cypress test

contributions/ServerSetup.md

@@ -61,7 +61,7 @@ This document doesn't provide instructions to install Java and Maven because the
 The following command will start a MongoDB docker instance locally:
 
 ```console
-docker run -p 127.0.0.1:27017:27017 --name appsmith-mongodb -e MONGO_INITDB_DATABASE=appsmith -v /path/to/store/data:/data/db mongo
+docker run -p 127.0.0.1:27017:27017 --name appsmith-mongodb -e MONGO_INITDB_DATABASE=appsmith -v /path/to/store/data:/data/db mongo --replSet rs0
 ```
 
 Please change the `/path/to/store/data` to a valid path on your system. This is where MongoDB will persist it's data across runs of this container.