Make TypeDB Cluster code snippets match the actual APIs and functionality

[jamesreprise]

Problem to Solve

Currently, we provide demonstrations of functionality on our TypeDB Cluster page that could be considered misleading.

Proposed Solution

Update the page to reflect Cluster's actual functionality in tandem with Console rather than 'demo' commands that aren't functional in practice.

[jamesreprise]

#197 goes some way to update this page, but we should still focus on updating the examples to bring them in line with actual functionality.