Add playground to website

[MonsieurV]

We could add a playground tab to the website, so users can easily try the functions.

For eg. we could try to embed this (which allows to loads BottomLine with Composer): https://phpsandbox.io/n/royal-resonance-w7nm-mt2lx

[MonsieurV]

We could even create the playground on the fly with the CLI (will requires a login tough, and to parse the output to get the sandbox link)

https://docs.phpsandbox.io/phpsandbox-cli/cli.html#export-command

[maciejczyzewski]

It's an excellent idea. Having a sandbox would be incredibly useful in:

1. README.md: to introduce the project to new users and provide a short code example of how to use it.
2. docs: each example in the documentation? Perhaps by generating tons of links to prepared environments.

edit: maybe some crazy "github actions" workflow?
for example, we could register an account for bottomline at phpsandbox.io; get the token and put psb login --token=${{secrets.PSB_TOKEN}} in workflow (that is performed only on tag/release to generate docs)