add option to use different portfolio file

[mhenke]

As a user, I would like to easily switch between different portfolio.yaml. For example, I have portfolio_mh.yaml which has my portfolio and portfolio_sh.yaml which has my wife's.

command might be:

• lak --file portfolio_mh.yaml -r list assets total aa al
• lak --file portfolio_sh.yaml -r list assets total aa al

[sarvjeets]

There is an an existing option that makes it easy to switch between multiple portfolios. You can specify different config files (which contain the name of portfolio file) with lak -c ....

Please take a look at the following links for more information:

• Format of lakrc (including how to specify different config files)
• Managing multiple portfolios