docs: update-hiero-cli

[rozekmichal]

Summary

Updates the Hiero CLI documentation to better match current @hiero-ledger/hiero-cli behavior and the official plugin model: refreshed hub content, aligned existing plugin pages with manifests/help output, added missing plugin guides, adjusted navigation, and tightened the scripting quickstart.

What changed

• Overview (hiero-cli/overview.mdx): Reworked intro, cards, and flows
• Plugins: Brought network, hbar, account, token, topic, config, plugin-management pages in line with the CLI; added full pages for batch (incl. HIP-551 context where relevant), schedule, contract, contract ERC-20, and contract ERC-721.
• Navigation (docs.json): Registered new routes and reordered the Plugins group to match the overview card order.
• Scripting (hiero-cli/scripting/quickstart.mdx): Aligned with official demo scripts and environment setup.
• Cross-links / UX: e.g. batch ↔ schedule where helpful; related links between contract token pages.
• Open source solutions (open-source-solutions.mdx): Adjusted Hiero CLI section presentation alongside the above.

Important note

The documentation changes in this pull request are based on a local build that is significantly more up to date than the latest release currently published on npm.