Replace @pxtrn/storybook-addon-docs-stencil

[janivo]

Storybook doctor logs revealed that we have two dependencies that might run our storybook into trouble. Both are dependencies of @pxtrn/storybook-addon-docs-stencil which is sadly no longer maintained. The source code seems rather compact, so we might be able to replace it by ourselves.

🩺 checking the health of your Storybook..

╭ Diagnostics ──────────────────────────────────────────────────────────────────────────────────────────────╮
│                                                                                                           │
│   Critical: The following dependencies are duplicated and WILL cause unexpected behavior:                 │
│   @storybook/core-events:                                                                                 │
│   7.6.17, 6.5.16                                                                                          │
│                                                                                                           │
│                                                                                                           │
│   Attention: The following dependencies are duplicated which might cause unexpected behavior:             │
│   @storybook/channels:                                                                                    │
│   7.6.17, 6.5.16                                                                                          │
│                                                                                                           │
│                                                                                                           │
│   You can find more information for a given dependency by running yarn why <package-name>                 │
│                                                                                                           │
│                                                                                                           │
│   Please try de-duplicating these dependencies by running yarn dedupe                                     │
│                                                                                                           │
│   -------                                                                                                 │
│                                                                                                           │
│   You can find the full logs in /Users/arbeit/Projects/elements/packages/storybook/doctor-storybook.log   │
│                                                                                                           │
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