set the command name in the examples without full path

Closes #16 (closed)

• Before:

❯ mpsd-software -h
usage: mpsd-software [-h] [-l {warning,info,debug}] [--version] {available,install,status,prepare} ...

Build software as on MPSD HPC.

    This tool builds software package sets (including toolchains for Octopus).
    It follows recipes as used on the MPSD HPC system and the (spack-based)
    Octopus buildbot. Compiled software is organised into MPSD software release
    versions (such as `dev-23a`) and CPU microarchitecture (such as `sandybridge`).
    
    Compiled packages and toolchains can be activated and used via `module load` as
    on the HPC system.
    
    Further documentation is available in the README.rst file, online at
    https://gitlab.gwdg.de/mpsd-cs/mpsd-software-manager/-/blob/main/README.rst

Command line usage:

   $> **/home/karnada/micromamba/envs/test-mpsd-installer/bin/**mpsd-software

options:
  -h, --help            show this help message and exit
  -l {warning,info,debug}
                        Set the log level
  --version             show program's version number and exit

actions:
  valid actions

  {available,install,status,prepare}
    available           What is available for installation?
    install             Install a software environment
    status              Show status: what is installed?
    prepare             Prepare installation of MPSD-release (dev only)

Examples:

    1. Query what package sets and toolchains are available for installation in
       release dev-23a
    
       $> /home/karnada/micromamba/envs/test-mpsd-installer/bin/mpsd-software available dev-23a
    
    2. Install foss2022a-serial toolchain from the dev-23a release
    
       $> /home/karnada/micromamba/envs/test-mpsd-installer/bin/mpsd-software install dev-23a foss2022a-serial
    
    3. Check what package sets and toolchains are installed from release dev-23a
    
       $> /home/karnada/micromamba/envs/test-mpsd-installer/bin/mpsd-software status dev-23a
    
       The `status` command also displays the `module use` command needed to load
       the created modules.

• After :

❯ mpsd-software -h
usage: mpsd-software [-h] [-l {warning,info,debug}] [--version] {init,available,install,status,prepare} ...

Build software as on MPSD HPC.

    This tool builds software package sets (including toolchains for Octopus).
    It follows recipes as used on the MPSD HPC system and the (spack-based)
    Octopus buildbot. Compiled software is organised into MPSD software release
    versions (such as `dev-23a`) and CPU microarchitecture (such as `sandybridge`).

    Compiled packages and toolchains can be activated and used via `module load` as
    on the HPC system.

    Further documentation is available in the README.rst file, online at
    https://gitlab.gwdg.de/mpsd-cs/mpsd-software-manager/-/blob/main/README.rst

Command line usage:

   $> mpsd-software

options:
  -h, --help            show this help message and exit
  -l {warning,info,debug}
                        Set the log level
  --version             show program's version number and exit

actions:
  valid actions

  {init,available,install,status,prepare}
    init                Initialise the MPSD software instance in the current directory
    available           What is available for installation?
    install             Install a software environment
    status              Show status: what is installed?
    prepare             Prepare installation of MPSD-release (dev only)

Examples:

    1. Query what package sets and toolchains are available for installation in
       release dev-23a

       $> mpsd-software available dev-23a

    2. Install foss2022a-serial toolchain from the dev-23a release

       $> mpsd-software install dev-23a foss2022a-serial

    3. Check what package sets and toolchains are installed from release dev-23a

       $> mpsd-software status dev-23a

       The `status` command also displays the `module use` command needed to load
       the created modules.