add script to autogenerate help from man pages

This creates main help like:

usage: apk [<OPTIONS>...] COMMAND [<ARGUMENTS>...]

Package installation and removal:
  add        Add packages to WORLD and commit changes
  del        Remove packages from WORLD and commit changes

System maintenance:
  fix        Check WORLD against the system and ensure consistency
  update     Update repository indexes
  upgrade    Install upgrades available from repositories
  cache      Commands related to the management of an offline package cache

Querying package information:
  info       Give detailed information about packages or repositories
  list       List packages matching a pattern or other criteria
  dot        Generate graphviz graphs
  policy     Show repository policy for packages

Repository maintenance:
  index      Create repository index file from packages
  fetch      Download packages from global repositories to a local directory
  manifest   Show checksums of package contents
  verify     Verify package integrity and signature

Miscellaneous:
  audit      Audit directories for changes
  stats      Show statistics about repositories and installations
  version    Compare package versions or perform tests on version strings

This apk has coffee making abilities.

And applet specific help like:

usage: apk add [<OPTIONS>...] PACKAGES...

Description:
  apk add adds the requested packages to WORLD and installs (or upgrades)
  them if not already present, ensuring all dependencies are met.

Global options:
  -f, --force           Enable selected --force-* options (deprecated)
  -i, --interactive     Ask confirmation before performing certain
                        operations
  -p, --root <DIR>      Install packages to DIR
  -q, --quiet           Print less information
  -U, --update-cache    Alias for '--cache-max-age 1'
  -v, --verbose         Print more information (can be specified twice)
  -V, --version         Print program version and exit
  -X, --repository <REPO>
                        Use packages only from the specified repository
  --allow-untrusted     Install packages with untrusted signature or no
                        signature
  --arch ARCH           Temporarily override architecture, to be combined
                        with --root
  --cache-dir CACHEDIR  Temporarily override the cache directory
  --cache-max-age AGE   Maximum AGE (in minutes) for index in cache before
                        it's refresh
  --force-binary-stdout
                        Continue even if binary data will be printed to the
                        terminal
  --force-broken-world  Continue even if WORLD cannot be satisfied
  --force-non-repository
                        Continue even if packages may be lost on reboot
  --force-old-apk       Continue even if packages use unsupported features
  --force-overwrite     Overwrite files in other packages
  --force-refresh       Do not use cached files (local or from proxy)
  --keys-dir KEYSDIR    Override directory of trusted keys
  --no-cache            Do not use any local cache path
  --no-network          Do not use the network
  --no-progress         Disable progress bar even for TTYs
  --print-arch          Print default arch and exit
  --progress            Show progress
  --progress-fd FD      Write progress to the specified file descriptor
  --purge               Delete modified configuration files on package
                        removal and uninstalled packages from cache on cache
                        clean
  --repositories-file REPOFILE
                        Override repositories file, see repositories
  --wait TIME           Wait for TIME seconds to get an exclusive repository
                        lock before failing

Commit options:
  -s, --simulate        Simulate the requested operation without making any
                        changes
  --clean-protected     Do not create .apk-new files in configuration
                        directories
  --overlay-from-stdin  Read list of overlay files from stdin
  --no-scripts          Do not execute any scripts
  --no-commit-hooks     Skip pre/post hook scripts (but not other scripts)
  --initramfs-diskless-boot
                        Enables options for diskless initramfs boot (e.g

Add options:
  --initdb              Initialize a new package database
  -l, --latest          Disables normal heuristics for choosing which
                        repository to install a package from, preferring only
                        repositories from which the latest version is
                        available
  -u, --upgrade         When adding packages which are already installed,
                        upgrade them rather than considering the requirement
                        fulfilled by the current installation
  -t, --virtual NAME    Instead of adding the specified packages to WORLD,
                        create a new virtual package with the listed packages
                        as its dependencies, then add that package to WORLD
  --no-chown            Do not change file owner or group