Improve and update the documentation

[AltiMario]

There are some issues with the documentation on how to set up the environment and run it due to the latest change in the tools we built.

Quick notes took

• clarify on cardano-connect the sample.env file has to be renamed into .env
• clarify that the TRAX credentials are set by the admin during the installation (email/pwd) and it will be required on the web login
• clarify that after TRAX login need to create the client for the connection (and point on it without credentials generates error 404)
• clarify that installing Logstore xAPI from https://moodle.org/plugins/logstore_xapi is wrong, has to be installed in our modified version
• to help more, suggest this link to follow https://extended.traxlrs.com/docs/2.0/first-steps
• idNumber is a praram "Identify users by user's idnumber"
• clarify that the command "php artisan trax:push2ipfs" is required every time there is a sync db-chain unless it is set in a cron
• clarify that the param REACT_APP_TX_RECEIVER is the address where the user's ADA will be sent