Feature/minor changes on readme and package

[gmazzap]

• Please check if the PR fulfills these requirements

• [x] The commit message follows our guidelines

• [ ] Tests for the changes have been added (for bug fixes/features)

• [ ] Docs have been added/updated (for bug fixes/features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

Improvement.

• What is the current behavior? (You can also link to an open issue here)

• What is the new behavior (if this is a feature change)?

No behavior change.

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)

No.

• Other information:

A few small improvements mostly in doc bloc and README. So small that I felt being fine a single PR instead of five, each with a super minor change.

There are only two small changes in code, but nothing relevant. Just improvement for inheritance considering classes are not final.

Anyway I added quite detailed information in each of the commits.

[gmazzap]

So can we merge? @Chrico @pablok34 ?

[gmazzap]

Cause all have approved, I'm merging