Feat: Add Exclude Paths Setting

[trganda]

PR for https://github.com/trganda/obsidian-attachment-management/issues/33

Change:

• You can now add the path of folder to "Exclude paths" to prevent the file under the folder be process by this plugin.
• By default, the "Exclude paths" will work on current folder, you can toggle "Exclude subpaths" to exclude subpaths also.