Bicep CLI - Implement `--help` per command

**Is your feature request related to a problem? Please describe.**

* The output of `bicep --help` is gigantic and hard to navigate in a terminal.
* Bicep CLI does not support help per command, like `bicep --help` for instance.

Current output of v0.27.1:

Click to expand

```
Bicep CLI version 0.27.1 (4b41cb6d4b)

Usage:
bicep build [options]
Builds a .bicep file.

Arguments:
The input file

Options:
--outdir Saves the output at the specified directory.
--outfile Saves the output as the specified file path.
--stdout Prints the output to stdout.
--no-restore Builds the bicep file without restoring external modules.
--diagnostics-format Sets the format with which diagnostics are displayed. Valid values are ( Default | Sarif ).

Examples:
bicep build file.bicep
bicep build file.bicep --stdout
bicep build file.bicep --outdir dir1
bicep build file.bicep --outfile file.json
bicep build file.bicep --no-restore
bicep build file.bicep --diagnostics-format sarif

bicep format [options]
Formats a .bicep file.

Arguments:
The input file

Options:
--outdir Saves the output at the specified directory.
--outfile Saves the output as the specified file path.
--stdout Prints the output to stdout.
--newline Set newline char. Valid values are ( Auto | LF | CRLF | CR ).
--indent-kind Set indentation kind. Valid values are ( Space | Tab ).
--indent-size Number of spaces to indent with (Only valid with --indentKind set to Space).
--insert-final-newline Insert a final newline.

Examples:
bicep format file.bicep
bicep format file.bicep --stdout
bicep format file.bicep --outdir dir1
bicep format file.bicep --outfile file.json
bicep format file.bicep --indent-kind Tab

bicep decompile [options]
Attempts to decompile a template .json file to .bicep.

Arguments:
The input file

Options:
--outdir Saves the output at the specified directory.
--outfile Saves the output as the specified file path.
--stdout Prints the output to stdout.
--force Allows overwriting the output file if it exists (applies only to 'bicep decompile' or 'bicep decompile-params').

Examples:
bicep decompile file.json
bicep decompile file.json --stdout
bicep decompile file.json --outdir dir1
bicep decompile file.json --force
bicep decompile file.json --outfile file.bicep

bicep lint [options]
Lints a .bicep file.

Arguments:
The input file

Options:
--no-restore Skips restoring external modules.
--diagnostics-format Sets the format with which diagnostics are displayed. Valid values are ( Default | Sarif ).

Examples:
bicep lint file.bicep
bicep lint file.bicep --no-restore
bicep lint file.bicep --diagnostics-format sarif

bicep decompile-params [options]
Attempts to decompile a parameters .json file to .bicepparam.

Arguments:
The input file

Options:
--outdir Saves the output at the specified directory.
--outfile Saves the output as the specified file path.
--stdout Prints the output to stdout.
--force Allows overwriting the output file if it exists (applies only to 'bicep decompile' or 'bicep decompile-params').
--bicep-file Path to the bicep template file that will be referenced in the using declaration

Examples:
bicep decompile-params file.json
bicep decompile-params file.json --bicep-file ./dir/main.bicep
bicep decompile-params file.json --stdout
bicep decompile-params file.json --outdir dir1
bicep decompile-params file.json --force
bicep decompile-params file.json --outfile file.bicepparam

bicep generate-params [options]
Builds parameters file from the given bicep file, updates if there is an existing parameters file.

Arguments:
The input file

Options:
--no-restore Generates the parameters file without restoring external modules.
--outdir Saves the output at the specified directory.
--outfile Saves the output as the specified file path.
--stdout Prints the output to stdout.
--output-format Selects the output format {json, bicepparam}
--include-params Selects which parameters to include into output {requiredonly, all}

Examples:
bicep generate-params file.bicep
bicep generate-params file.bicep --no-restore
bicep generate-params file.bicep --stdout
bicep generate-params file.bicep --outdir dir1
bicep generate-params file.bicep --outfile file.parameters.json
bicep generate-params file.bicep --output-format bicepparam --include-params all

bicep publish --target
Publishes the .bicep file to the module registry.

Arguments:
The input file (can be a Bicep file or an ARM template file)
The module reference

Options:
--documentation-uri Module documentation uri
--with-source [Experimental] Publish source code with the module
--force Overwrite existing published module or file

Examples:
bicep publish file.bicep --target br:example.azurecr.io/hello/world:v1
bicep publish file.bicep --target br:example.azurecr.io/hello/world:v1 --force
bicep publish file.bicep --target br:example.azurecr.io/hello/world:v1 --documentation-uri https://github.com/hello-world/README.md --with-source
bicep publish file.json --target br:example.azurecr.io/hello/world:v1 --documentation-uri https://github.com/hello-world/README.md

bicep restore
Restores external modules from the specified Bicep file to the local module cache.

Arguments:
The input file

bicep [options]
Options:
--version -v Shows bicep version information
--help -h Shows this usage information
--license Prints license information
--third-party-notices Prints third-party notices

bicep build-params
Builds a .json file from a .bicepparam file.

Arguments:
The input Bicepparam file

Options:
--bicep-file Verifies if the specified bicep file path matches the one provided in the params file using declaration
--outfile Saves the param output json as the specified file path.
--stdout Prints the param and bicep json output to stdout.
--no-restore Builds the bicep file (referenced in using declaration) without restoring external modules.
--diagnostics-format Sets the format with which diagnostics are displayed. Valid values are ( Default | Sarif ).

Examples:
bicep build-params params.bicepparam
bicep build-params params.bicepparam --stdout
bicep build-params params.bicepparam --outfile otherParams.json
bicep build-params params.bicepparam --no-restore
bicep build-params params.bicepparam --diagnostics-format sarif
```

**Describe the solution you'd like**

Add ability to do `bicep --help` or `bicep --help `.

* Example: `bicep build --help` or `bicep --help build`

Start by running the existing `bicep --help` output and inspect how the listed commands are dispatched. Add command-specific help for forms such as `bicep build --help` and `bicep --help build`, then verify that each listed command displays focused usage information without changing normal command behavior.

Written by the indexing model from the issue text.