chore(release): simplify karma-webpack release

[joshwiens]

Please check if the PR fulfills these requirements

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior? (You can also link to an open issue here)
The existing release process is a bit cumbersome for someone not accustomed to it. New process ensures you can't publish a version without the lib being built.

What is the new behavior?

• Removes custom scripting in favor of standard-version
• Add supporting npm scripts
• Add RELEASE.md with clear instructions for the entire release workflow.

Does this PR introduce a breaking change?

• Yes
• No