Add: Board Name function

[Rushaway]

Description

Add board name based on the configuration title in Settings - Title

Motivation and Context

Allow usage of the configured Title in Settings by using {$board_name} instead of {$title} who return the page name (Ex : Dashboard)

How Has This Been Tested?

Works in https://bans.nide.gg/ without any errors.

Screenshots (if appropriate):

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [X] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [X] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [X] I have updated the documentation accordingly.
• [X] I have read the CONTRIBUTING document.