feat: [GH-722] Add Calendar Integration

[beanbeanjuice]

Pull Request

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Description

Adds a calendar integration so that users can input their own calendar for others to view.

Fixes GH-722.

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Type of Change

• Bug Fix (Small Non-Code Breaking Issue)
• Bug Fix (Critical Code Breaking Issue)
• Feature (Something New Added to the Code)
• Improvement (Improving An Existing Section of Code)
• Documentation Update
• Security Vulnerability

Changes

• Internal Code
• Documentation
• Other: _____

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Test Configuration

• Hardware:
  • CPU: AMD Ryzen 7 5800x3D
  • GPU: Nvidia RTX 3080
  • RAM: 32 GB DDR4 @ 3600 Mhz
• JDK: Java OpenJDK 21
• Platform: Windows 11

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Checklist

• The code follows the style guidelines.
• A self-review of the code was performed on GitHub.
• Appropriate comments and javadocs were added in your code.
• Appropriate tests were added.
• Appropriate changes have been made to the documentation.
• Appropriate changes have been made to the README.md file.

[beanbeanjuice]

Bugged a bit. If you copy the text, you can delete ANY calendar from DMs.

Might need to implement some sort of "caller" in the back-end.