Add CLI & Env Variable Support for Aliases

#14 added aliases to the config file, we should also figure out a format for passing them in as CLI options & through environmental variables. 

Maybe allow multiple CLI flags like `--some-flag JOURNAL_CURRENCY:ALPHAVANTAGE_TICKER` to assemble the list, maybe a similar alias format deliminated with semicolons for the env var like `SOME_VAR="JCUR1:ATICKER1;JCUR2:ATICKER2"`