doc command as per man page fails due missing dependency

[Cesar Rabak]

According picolisp man page (about 50th line):

      Here you can access the reference manual

              : (doc)

       and the online documentation for most functions,

              : (doc 'vi)

However when installed through apt this fails with the info that 'w3m' is not available.

Once apt install w3m is performed, the documentation function works like a charm!

Please include the w3m as dependency for picolisp package.

TIA