feat: add tutorial for - Writing Your First Smart Contract

[anataliocs]

Title:
Writing Your First Smart Contract

Referenced here: https://use.ink/tutorials/ideas/

Description:
Step-by-step instructions on creating a simple ink! contract, explaining key concepts like storage and messages.

PR:
#547

Using template:
https://use.ink/tutorials/template/

• Review contribution guidelines: https://use.ink/tutorials/guide/
• Create issue with tutorial details feat: add tutorial for - Writing Your First Smart Contract #545
• Fork ink-docs repo and create branch referencing issue https://github.com/anataliocs/ink-docs/tree/feat-add-tutorial-for---Writing-Your-First-Smart-Contract-%23545
• Update Sidebar structure tutorials/sidebar.js
• Create markdown file from template tutorials/template.md and place in correct position as per tutorials/sidebar.js
• Build out each section in template with appropriate details and code samples
• Create companion Github repo with supporting functional code and direct link in tutorial: https://github.com/anataliocs/helloink
• Build and run locally using pnpm (Reference README) using pnpm install && pnpm start and navigate to http://localhost:8080/tutorials/writing-your-first-smart-contract
• Using local build:
  • Verify successful build
  • Review look and feel of tutorial(Make sure it flows intuitively and syntax+formatting is correct)
  • Validate code correctness(Build, compile, test, static analysis, manual+AI code review)
  • Reproduce each step to ensure validity
  • Local tutorial URL: http://localhost:8080/tutorials/writing-your-first-smart-contract
• Create PR referencing issue, tutorial details and Github companion repo: feat: add tutorial for - writing your first smart contract #545 #547
• Mention PR in Ink Alliance Telegram requesting review
• After review from the ink! team, update the llms.txt file for parsing by AI coding agents