Provider groups description and new providers per version table in DOCS

[panilya]

No description provided.

[what-the-diff]

• Added new enum TextBlock with header and group descriptions
• Changed the way of getting a provider's group name (e.g base, sport) from packageName to using reflection API
• Refactored extractCommentFromJavadoc method: added extracting since tag for each Faker(provider), removed fakersWithoutSinceTag parameter
• Created providersPerVersionTable() method that extracts all versions in which were introduced new providers and counts them per version; also it calculates total number of providers per version
• Updated constructHeaderInProvidersFile() by adding table with count of new providers per Datafaker version + total number of existing ones at this moment