feat: zero-knowledge proof guide

[mysteryon88]

Closes #111

Add Zero-Knowledge Proofs Guide for TON

Summary

This PR adds a comprehensive guide for working with zero-knowledge proofs on the TON blockchain, covering the complete workflow from circuit creation to on-chain verification.

Changes

Documentation

• Created new guide: contract-dev/zero-knowledge.mdx
  • Complete step-by-step tutorial for ZK-proofs on TON
  • Covers Circom circuit creation, compilation, and trusted setup
  • Includes examples for FunC, Tolk, and Tact verifier contracts
  • Provides integration examples with Arkworks (Rust) and Gnark (Go)
  • Features local and on-chain proof verification examples

Navigation

• Added sidebar entry: Added contract-dev/zero-knowledge to the "Contract development" section in docs.json

Dictionary Updates

• Added words to custom dictionary (resources/dictionaries/custom.txt)
• Removed 2 words from ban list (resources/dictionaries/two-letter-words-ban.txt)

Quality Assurance

• Ran npm run check:spell - all spelling checks passed

[github-actions]

Skipping AI review because this PR is from a fork. A maintainer can start the review by commenting /review in this PR.

[Kaladin13]

/review

[github-actions]

Thanks for the update—across contract-dev/zero-knowledge.mdx, there are several suggestions to align structure, tone, and safety; please apply the inline suggestions.

[Kaladin13]

Great article, lets fix AI review results and my comments

[mysteryon88]

@Kaladin13, I made corrections, you can check it.

[Kaladin13]

@mysteryon88 Lint fails, please run npx remark -o --silent --silently-ignore contract-dev/zero-knowledge.mdx on your branch for this

[mysteryon88]

@Kaladin13 Fixed

[Kaladin13]

Good!