Improve documentation on how to test Booster apps

[BorjaZarco]

Documentation bugs and improvements

Some work is necessary to improve the documentation and make the testing experience on Booster better

Description

Some of the issues found when trying to test a Booster application were:

1. It is required to install the following libraries: sion, sion-chai, chai, chai-promised and their respective @types dependencies. Perhaps they could be already installed with the boost:new project command (or using a new specific command to setup testing)
2. The tests folder should be moved to the tsconfig.json. There is an issue here. Apparently, ./src is set to be the rootDir. This forces the test folder to be inside it in order to be transpiled
3. One example on the docs is deprecated. The following code:

const register = new Register('request-id-1') 

Does not work because the Register constructor requires two arguments. It is not clear what the second argument is.

[javiertoledo]

This is a Discord conversation related to this issue where many users discuss about the right way to configure Jest to work in Booster apps: https://discord.com/channels/763753198388510780/1044231044251013190

[Will-Marriott]

@BorjaZarco Hi - is this still open?

[javiertoledo]

Yes @Will-Marriott, it's open, are you considering working on it?

[Will-Marriott]

Yes @Will-Marriott, it's open, are you considering working on it?

Yes I'd like to work on it :)

[javiertoledo]

Awesome, thanks! I'll assign the issue to you :-)