UPPCL-P2P: Starter Pack

### Description:
Documentation - Prepare a Starter Kit that covers these items:

Tech Aspects:
- Beckn Overview
- Beckn Overview - What is Beckn
- Open Network Tech Documentation
- Sandbox User Guide
- Beckn Sandbox
- Example JSONs
- Postman Collections
- Sample JSONs
- ONIX Documentation for Network Deployments
- ONIX User Guide
- ONIX Implementation Guide

Once documents are prepared, add to the confluence page here: [Confluence Page](https://fide-official.atlassian.net/wiki/spaces/TPP/pages/399441921/VISTAAR) so that it's ready to be shared with users.

### Goals:
- [ ] Create comprehensive Beckn Overview documentation.
- [ ] Compile Open Network tech documentation including Sandbox User Guide, Example JSONs, Postman Collections, and Sample JSONs.
- [ ] Prepare ONIX documentation including User Guide and Implementation Guide.
- [ ] Add all documents to the specified Confluence page.

### Expected Outcome:
- A complete and accessible Starter Kit for VISTAAR that includes all necessary technical documentation and is readily available on the Confluence page.

### Acceptance Criteria:
- [ ] Beckn Overview documentation is prepared and reviewed.
- [ ] Open Network tech documentation is compiled and organized.
- [ ] ONIX documentation for network deployments is completed.
- [ ] All documents are uploaded to the Confluence page.

### Mockups / Wireframes:
NA

### Product Name:
Beckn

### Domain:
AgriNet

### Tech Skills Needed:
Technical Writing, Beckn Protocol Knowledge, ONIX Documentation

### Complexity:
High

### Category:
Documentation

### Sub Category:
Starter Kit

Start by reviewing the linked Confluence page and inventory the requested Beckn Overview, Open Network, sandbox, example and sample JSON, Postman Collection, and ONIX materials. Confirm the required content and review process with the project maintainers, then use the acceptance criteria to verify that each document is prepared, organized, reviewed, and added to the VISTAAR page.

Written by the indexing model from the issue text.