Various Fixes

See merge request !2

BREAKING CHANGE: `image` is now the image name, the `tag` input defines the image tag

Already described in the overview.

Move links to the end of the document.

Invalidate `node_modules` when the lockfile changes.

Keep the `npm` cache around separately to speed up installs.

The cache is hashed on the `package-lock.json`.

It is safe to share the cache across the whole instance as if the
hash matches, we are guaranteed to have installed the same modules.

This is recommended upstream to use the scoped `CI_JOB_TOKEN`.

However, we must allow the user to override `NPM_TOKEN` because
there are times where the `CI_JOB_TOKEN` does not have the correct
permissions.

It should be entirely up to the user to decide the strategy.

The default of `fetch` is significantly faster for large projects.

A default of `clone` will be a regression for those projects.

The only time a full clone is needed is if one has deleted a tag and
the remote CI has cached that tag in the fetch. This is easy to fix
by switching over the CI settings to clone for a single run or adding
a `GIT_STRATEGY` CI variable for a short period to clean out the cache.

We should cache _per-project_ and use a unique key.

Using a simple key such as `node`:

- The cache will be shared across _all_ projects using the component
    - The cache will just slowly grow
    - It would be possible to use modules install by other projects
- Conflict with any other cache specified as `node`

_Technically_, we are dogfooding the template and testing it.

However, the result of the job on protected branches is that it
deploys the component.

Semantic-release component

See merge request !1