Readme.me: wrong instructions

I know it's work in progress and that in the future the script will work as described, but for now the instructions should read:

Build it
seacan myapp_seacan.toml

instead of:
seacan build --config myapp_seacan.toml

Regards,

C.

Open Readme.me and compare the current build instructions with the issue's proposed commands. Update the example to use `seacan myapp_seacan.toml` instead of `seacan build --config myapp_seacan.toml`; the work is done when the README matches the current script behavior.

Written by the indexing model from the issue text.