feat: ignore some directories & files in files achievements

[BoxBoxJason]

This PR adds some default ignore files & directories for the extension achievements.

The user can now configure their achievements.ignore.files and achievements.ignore.directories settings to select paths they want to ignore when progressing their achievements.

Fixes #41

[Copilot]

Pull request overview

This PR introduces configurable ignore lists for file-based achievement progression, aimed at preventing events from generated folders and VCS internals (e.g., .git) from triggering achievements (Fixes #41).

Changes:

• Add new configuration settings for achievements.ignore.files and achievements.ignore.directories (with defaults).
• Filter file, rename, text-change, and diagnostics listeners to ignore matching paths.
• Extend the file-listener test suite to validate ignore behavior for common paths (e.g., .git, node_modules, lockfiles).

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/listeners/files.ts	Adds default ignore lists and a shouldIgnoreUri gate used by multiple file-related listeners.
src/config/config.ts	Extends the config shape with ignore.files / ignore.directories and parses those settings.
src/test/listeners/files.test.ts	Adds tests ensuring ignored paths do not trigger progression updates.
package.json	Contributes the new settings and their defaults to the extension configuration schema.
README.md	Documents the new ignore settings.

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