style(stark-all): re-format files with latest Prettier version. Include MD files in Prettier auto formatting.

[christophercr]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/NationalBankBelgium/stark/blob/master/CONTRIBUTING.md#-commit-message-guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[ ] Feature
[X] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

Formatting applied using a previous version of Prettier. MD files were not included in the set of files to be auto-formatted.

What is the new behavior?

Re-format files using the latest version of Prettier. MD files also auto-formatted.

Important: the CHANGELOG.md file is excluded from this auto-formatting because it is auto-generated on every release!

Does this PR introduce a breaking change?

[ ] Yes
[X] No

[coveralls]

Coverage increased (+0.01%) to 94.259% when pulling 2d56514 on christophercr:feature/fix-formatting into 18ddc7a on NationalBankBelgium:master.