Add npmignore

[wallstop]

Description

• Add npmignore for better npm publishing
• Update package.json with additional file alignment
• Update version to 2.1.8

Related Issue

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Refactor (code change that neither fixes a bug nor adds a feature)

Checklist

• All tests pass locally
• Code is properly formatted
• I have added tests that prove my fix is effective or my feature works
• I have updated the documentation accordingly
• I have updated the CHANGELOG
• My changes do not introduce breaking changes, or breaking changes are documented

[Copilot]

Pull request overview

This PR tightens npm/UPM publishing output by adding explicit packaging rules, and bumps the project version to 2.1.8.

Changes:

• Add a new .npmignore to exclude dev-only and build artifacts from published packages.
• Add a files allowlist in package.json to control what gets shipped.
• Bump version references to 2.1.8 (package.json, changelog, docs banner).

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 3 comments.

File	Description
package.json	Bumps version and introduces a files allowlist for publish contents.
.npmignore	Adds publish-time ignore rules aligned with repo/dev artifacts.
CHANGELOG.md	Adds a 2.1.8 entry describing the publishing fix.
docs/images/DxMessaging-banner.svg	Updates the displayed version badge to v2.1.8.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 6 changed files in this pull request and generated 2 comments.