chore: for each command, add markdown containing help text

[harp-intel]

This pull request adds automatic generation of command documentation for the perfspect tool and updates the README.md to reference these new docs. The main changes are the introduction of a Makefile target that creates Markdown documentation for each command and subcommand, and the enhancement of the README to link to these docs for easier access to command-line options and help texts.

Documentation generation and integration:

• Added a docs Makefile target that generates Markdown documentation for all main commands (report, benchmark, metrics, telemetry, flamegraph, lock, config) and selected subcommands (metrics:trim, config:restore) by extracting help text from the CLI and saving it to the docs directory. (Makefile)
• Created new Markdown files for each command and subcommand containing their help texts and usage examples: docs/perfspect.md, docs/perfspect_benchmark.md, docs/perfspect_config.md, docs/perfspect_config_restore.md, docs/perfspect_flamegraph.md. [1] [2] [3] [4] [5]

README enhancements:

• Updated the command table in README.md to include direct links to the generated documentation for each command.
• Replaced inline help references throughout the README with links to the relevant Markdown documentation files, improving discoverability and consistency. [1] [2] [3] [4] [5] [6] [7]