docs: adapted new structure for states and workflows

[musslick]

Description

The old state and workflow documentation was obscure, in part because relevant information was hidden in "Examples" sections, and because the information was distributed across section. The PR attempts to consolidate State and Workflow information into one section with the following structure:

• States and Workflows:
  • Home:
  • AutoRA Variables:
  • States:
    • Overview:
    • Basic Usage:
    • Combining Experimentalists with States:
  • Workflows with States:
    • Overview:
    • Dynamically Altering the State:
  • Workflows for HPCs:
    • "Command Line Interface"
    • "Basic Usage"
    • "Using Cylc"
    • "Using Cylc and Slurm"

Type of change

Delete as appropriate:

• docs: Documentation only changes