Add inside the User Guide documentation section a basic usage section and example

[davideicardi]

Fixes #3555

(My english is quite bad, so feel free to fix any error or add any improvements)

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[aledbf]

@davideicardi please sign the CLA

[davideicardi]

/check-cla

[ElvinEfendi]

Some minors comments, please squash your commits after.

[davideicardi]

Thanks @ElvinEfendi , corrections done

[ElvinEfendi]

/lgtm
/approve

thanks @davideicardi

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This pull-request has been approved by: davideicardi, ElvinEfendi

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