[FR] Enhance functionality for note creation and path handling

[SSmJaE]

Describe your request

Current Issues

1. Limited Command Functionality

Currently, when using PDF++ commands, it only allows creating new notes. We need a dedicated command that:

• Only opens existing corresponding notes
• Doesn't perform any additional operations

2. Path Resolution Issues

There's a problem with note generation paths when a specific folder path is configured:

• When a new folder path is specified in settings
• New note paths are incorrectly concatenated from the specified folder instead of starting from the vault root directory

Expected Behavior

Command Enhancement

• Add a new command that specifically handles opening existing notes
• Keep the current note creation functionality separate
• Allow users to choose between creating new notes or opening existing ones

Path Resolution

• All paths should be resolved from the vault root directory
• When specific folders are configured, the path should still maintain proper resolution from root
• Example:
  • Vault root: /
  • New note folder path: /!uncategorized/
  • Plugin configured folder: /academic/_notes/
  • New note path should be: /academic/_notes/note.md (absolute path)
  • Current behavior: !uncategorized/academic/_notes/note.md (incorrect concatenation)