MkDocs preview: https://06ffdba6.dd-docs-preview.pages.dev

Fern preview: https://nvidia-preview-pr-608.docs.buildwithfern.com/nemo/datadesigner​

Notebook tutorials are rendered without execution outputs in previews.

Greptile Summary

This PR adds a new "Have It Your Way" dev note introducing Data Designer's plugin framework now that plugins have graduated from experimental, along with reusable CSS helpers for devnote image layout and the removal of the experimental warning banners from the plugin reference pages.

• The dev note is added in both MkDocs (docs/devnotes/posts/have-it-your-way.md) and Fern (fern/versions/v0.5.8/pages/devnotes/posts/have-it-your-way.mdx) formats, with navigation entries correctly placed at the most-recent-first position in both mkdocs.yml and fern/versions/v0.5.8.yml.
• CSS additions in docs/css/style.css introduce devnote-dek, devnote-float-right, devnote-section-graphic, and devnote-clear utility classes with a responsive breakpoint at 60em; experimental warning banners are removed from three Fern plugin pages (overview.mdx, example.mdx, filesystem_seed_reader.mdx).

Important Files Changed

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[User installs plugin package] --> B[Entry point registered\nvia pyproject.toml]
    B --> C[Data Designer discovers\nplugin at startup]
    C --> D[User imports plugin\nconfig class]
    D --> E[User adds to\nDataDesignerConfigBuilder]
    E --> F{Plugin type?}
    F -->|Seed Reader| G[build_manifest\nhydrate_row]
    F -->|Column Generator| H[generate column\nwith dependency ordering]
    F -->|Processor| I[transform records\nbefore/after generation]
    G --> J[Data Designer executes\nnormal workflow]
    H --> J
    I --> J

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
docs/devnotes/posts/have-it-your-way.md:231-255
**`extract_markdown_sections` is undefined in the shown code**

The `impl.py` block is framed as a walkthrough of a complete file, but `extract_markdown_sections` is called without being imported or defined anywhere in the snippet. A reader copying this code would get a `NameError` immediately. The prose does note "the parser can still be a normal helper function," but there is no indication of where that function comes from — whether it should be defined earlier in `impl.py`, imported from a sibling module, or supplied by the user. The same gap exists in the Fern mirror at `fern/versions/v0.5.8/pages/devnotes/posts/have-it-your-way.mdx`. Adding a brief comment inside the code block or a preceding prose sentence pointing readers to the recipe link for the complete version would resolve the ambiguity.

_{Reviews (10): Last reviewed commit: "docs: link v0.6.0 release" | Re-trigger Greptile}

Thanks @nabinchha, good call. I added a short note at the end of the “Where Plugins Fit” section that points readers to custom columns as the right starting point for prototyping column-generator behavior or for one-off project-specific columns. It also says to promote that logic to a column generator plugin once it needs a stable config schema, tests, packaging, docs, or reuse across teams.