Add support for JohnnyDecimal folder structure

[MahmadSharaf]

Support Johnny Decimal folder structure

Overview

This feature allows users who adapt Johnny Decimal folder structure, which is numbering their folder names, to have the flexibility to set their Folder Note without this numbering system.
However, it doesn't strictly require all folders to have numbers, so folders that have the exact name as the folder note will still pass through.

Changes

main.ts:

• Add flag useJohnnyDecimal to handle folders with numbering system.
• Created helper method removeJohnnyDecimal to return the parent folder without the numbers, if found.
• Update IsFolderNote and getFileTreeRepresentation functions to support Johnny Decimal feature

README.md

• Added a description for the newly introduced feature.