docs: readme refactoring

[DavideMininni-Fincons]

Preflight Checklist

• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the pull request tracker for a Pull Request (PR) that matches the one I want to submit, without success.

Issue

This PR Closes #1977

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)

See Review Guidelines for more information what is checked during review process.

Changes

Changes in this pull request:

• the readme.md in the boilerplate folder has been revisited adding paragraphs;
• the CODING_STANDARD.md has been updated;
• all the readme.md files, except for the internals/timetable, has been refactored using paragraphs.

Browsers

I tested the build on the following browsers:

• Firefox Desktop
• Chrome Desktop
• Edge Desktop
• Safari Desktop
• Chrome Mobile
• Safari Mobile

Screen readers

I tested the build on the following browsers:

• JAWS Firefox Desktop
• JAWS Chrome Desktop
• NVDA Firefox Desktop
• NVDA Chrome Desktop
• VoiceOver Safari Desktop
• VoiceOver Chrome Desktop
• VoiceOver Safari Mobile
• Android Accessibility Suite Chrome Mobile

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

Does this introduce a breaking change?

• Yes
• No

Other information

[codecov-commenter]

Codecov Report

Merging #1996 (b9de383) into master (ab917b0) will decrease coverage by 18.13%.
Report is 1748 commits behind head on master.
The diff coverage is 30.55%.

❗ Current head b9de383 differs from pull request most recent head 248a60c. Consider uploading reports for the commit 248a60c to get more accurate results

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

@@             Coverage Diff             @@
##           master    #1996       +/-   ##
===========================================
- Coverage   54.85%   36.72%   -18.13%     
===========================================
  Files          49      288      +239     
  Lines        1659    10865     +9206     
  Branches      406     2382     +1976     
===========================================
+ Hits          910     3990     +3080     
- Misses        671     6617     +5946     
- Partials       78      258      +180     

Files	Coverage Δ
...c/components/sbb-action-group/sbb-action-group.tsx	100.00% <100.00%> (ø)
...mponents/sbb-alert-group/sbb-alert-group.events.ts	100.00% <100.00%> (ø)
src/components/sbb-alert/sbb-alert.events.ts	100.00% <100.00%> (ø)
...onents/sbb-autocomplete/sbb-autocomplete.events.ts	100.00% <ø> (ø)
src/components/sbb-card-badge/sbb-card-badge.tsx	100.00% <100.00%> (+11.11%)	⬆️
src/components/sbb-card/sbb-card.stories.tsx	0.00% <ø> (ø)
src/components/sbb-card/sbb-card.tsx	90.00% <ø> (ø)
.../sbb-checkbox-group/sbb-checkbox-group.stories.tsx	0.00% <ø> (ø)
...mponents/sbb-checkbox-group/sbb-checkbox-group.tsx	33.33% <ø> (ø)
src/components/sbb-checkbox/sbb-checkbox.events.ts	0.00% <ø> (ø)
... and 55 more

... and 239 files with indirect coverage changes

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[dauriamarco]

LGTM 👍 just a couple of comments.