docs(examples): add end-to-end tokenfactory minting example

[Karry2019web]

Closes #39

Summary

Adds a complete end-to-end example for the x/tokenfactory module at examples/tokenfactory/, containing:

1. README.md — narrated walkthrough covering the full lifecycle:

   • Setup (local node, keys, genesis)
   • Create denom (permissionless factory/{creator}/{subdenom})
   • Set denom metadata (name, symbol, display units)
   • Mint tokens (to self and directly to recipient)
   • Bank transfer (the new denom behaves like any native coin)
   • Burn tokens (from any address as admin)
   • Force transfer (admin power)
   • Change admin / renounce admin
   • Various query commands (params, denom-authority-metadata, denoms-from-creator, bank queries)
   • Cleanup

2. run.sh — automated shell script that runs through every step with colored output, balance verification, and error handling.

What's demonstrated

Step	Command	Notes
Create	safrochaind tx tokenfactory create-denom	Permissionless, namespaced by creator
Metadata	modify-metadata	JSON metadata for wallet rendering
Mint	mint with mint_to_address	Admin can mint to any address
Transfer	bank send	Standard Cosmos SDK
Burn	burn with burn_from_address	Admin can burn from any address
Force transfer	force-transfer	Admin power
Change admin	change-admin	Transfer or renounce (burn address)
Query	denom-authority-metadata, denoms-from-creator	Various tokenfactory queries

Implementation notes

• Uses the autocli commands from x/tokenfactory/module/autocli.go
• Bech32 prefix addr_safro, bond denom usaft (testnet)
• Denom creation fee: 10,000,000 usaft (from DefaultParams())
• Script handles errors gracefully with set -euo pipefail
• All addresses and denoms are dynamically resolved