fix: adds the package.json to the dist folder of the published library

[gclapperton]

What does this PR do?

Adds the package.json to the dist folder of the published library.

The library exports it's version and so needs to be able to inspect it's own package.json file. The new TypeScript compilation did not include it in the dist directory as expected

Note:

• npm link does not appear to install the final package (ie. doesn't respect things like files)
• semantic release updates the package version before build is run in the prepublish step

How should this be manually tested?

Run npm pack to verify that the package.json is included in the dist directory and then npm install <policyRepoPath>/ snyk-policy-0.0.0.tgz before testing in Registry

[snyksec]

:tada: This PR is included in version 2.0.1 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket: