Ignore files

[gotbahn]

As was discovered in https://github.com/zattoo/web-shared/pull/1132 not all changes shall lead to changelog updates, for example, test files in packages. Therefore we shall support ignore patterns, to exclude unwanted checks.

Acceptance

• exclude option added to inputs
• exclude is optional
• exclude accepts list of glob patterns
• when pattern matches file, it excluded from the changelog scope