added 7 new guides for contracts (#5467)

## Problem solved

Short description of the bug fixed or feature added

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## PR-Codex overview
This PR focuses on restructuring and enhancing the documentation for various modular contract types in the `pre-built-modular` section, including updates to navigation, descriptions, and deployment steps.

### Detailed summary
- Renamed `Pre-built Contracts` to `Pre-built Modular` in the sidebar.
- Added detailed documentation for:
  - `NFT Drop`
  - `Token`
  - `Token Drop`
  - `Edition Drop`
  - `Open Edition`
  - `Edition`
  - `NFT Collection`
- Included images and steps for deploying each contract type.
- Updated links and metadata for better navigation and user experience.

> ✨ Ask PR-Codex anything about this PR by commenting with `/codex {your question}`
https://linear.app/thirdweb/issue/DEVX-1828/7-guides-for-contracts
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Author: saminacodes