Make help command remind users about help-advanced command

[alexey-tereshenkov-oxb]

Work towards #13363

Subsystems:

With advanced options:

$ ./pants help anonymous-telemetry

`anonymous-telemetry` subsystem options
---------------------------------------

Options related to sending anonymous stats to the Pants project, to aid development.
 
Activated by pants.core
Config section: [anonymous-telemetry]
 
None available.
There are advanced options which you can list by running `./pants help-advanced anonymous-telemetry`

$ ./pants help yapf

`yapf` subsystem options
------------------------

A formatter for Python files (https://github.com/google/yapf).
 
Activated by pants.core
Config section: [yapf]
 
  --[no-]yapf-skip
  PANTS_YAPF_SKIP
  skip
      default: False
      current value: False
      Don't use yapf when running `./pants fmt` and `./pants lint`.

  --yapf-args="[<shell_str>, <shell_str>, ...]"
  PANTS_YAPF_ARGS
  args
      default: []
      current value: []
      Arguments to pass directly to yapf, e.g. `--yapf-args="--no-local-style"`.
      
      Certain arguments, specifically `--recursive`, `--in-place`, and `--parallel`, will be ignored because Pants takes care of finding all the relevant files and running the formatting in parallel.

There are advanced options which you can list by running `./pants help-advanced yapf`

Without advanced options:

$ ./pants help cli

`cli` subsystem options
-----------------------

Options for configuring CLI behavior, such as command line aliases.
 
Activated by 
Config section: [cli]
 
  --cli-alias="{'key1': val1, 'key2': val2, ...}"
  PANTS_CLI_ALIAS
  alias
      default: {}
      current value: {
          "all-changed": "--changed-since=HEAD --changed-dependees=transitive",
          "run-pyupgrade": "--backend-packages=pants.backend.experimental.python.lint.pyupgrade fmt"
      } (from pants.toml)
      Register command line aliases.
      Example:
      
          [cli.alias]
          green = "fmt lint check"
          all-changed = "--changed-since=HEAD --changed-dependees=transitive"
      
      This would allow you to run `./pants green all-changed`, which is shorthand for `./pants fmt lint check --changed-since=HEAD --changed-dependees=transitive`.
      
      Notice: this option must be placed in a config file (e.g. `pants.toml` or `pantsrc`) to have any effect.

Goals:

With advanced options:

$ ./pants help tailor

`tailor` goal options
---------------------

Auto-generate BUILD file targets for new source files.
 
Activated by pants.core
Config section: [tailor]
 
  --[no-]tailor-check
  PANTS_TAILOR_CHECK
  check
      default: False
      current value: False
      Do not write changes to disk, only write back what would change. Return code 0 means there would be no changes, and 1 means that there would be.

There are advanced options which you can list by running `./pants help-advanced tailor`

Without advanced options:

$ ./pants help run

`run` goal options
------------------

Runs a binary target.

This goal propagates the return code of the underlying executable.

If your application can safely be restarted while it is running, you can pass `restartable=True` on your binary target (for supported types), and the `run` goal will automatically restart them as all
relevant files change. This can be particularly useful for server applications.
 
Activated by pants.core
Config section: [run]
 
  --run-args="[<shell_str>, <shell_str>, ...]"
  ... -- [<shell_str> [<shell_str> [...]]]
  PANTS_RUN_ARGS
  args
      default: []
      current value: [] (from command-line flag)
      Arguments to pass directly to the executed target, e.g. `--run-args="val1 val2 --debug"`

  --[no-]run-cleanup
  PANTS_RUN_CLEANUP
  cleanup
      default: True
      current value: True
      Whether to clean up the temporary directory in which the binary is chrooted. Set to false to retain the directory, e.g., for debugging.

Targets do not have a concept of an option and therefore do not need any special handling.

[alexey-tereshenkov-oxb]

Example appearance in the terminal:

[kaos]

Thanks, good idea!

[kaos]

Nice.

I'll await a second opinion on this before merging. In the meantime if you'd like to fix the ./pants reference, that'd be great. Thanks. :)

[Eric-Arellano]

Lovely! It's neat how few lines this took to do. Thanks!

[Eric-Arellano]

Btw, we're having some issues getting pants_bin() to pass in CI. Feel free to go back to using ./pants while we figure that out - no need to block your PR. This looks great!

[Eric-Arellano]

Thanks for the great contribution!