Markdown for READMEs and docs: preview before you publish

README files, internal runbooks and lightweight marketing pages still ship as Markdown more often than not. The failure mode is familiar: bold lines that should be lists, fences that never close and JSON blocks copied from a stale Postman tab. Previewing before merge turns half of those failures into cheap fixes.

Who this is for

• Engineers owning repo READMEs and contributing guides.
• Analysts writing method notes or shareable how-tos alongside notebooks.

Why side-by-side preview matters

Markdown is sparse by design; errors hide until render time. A live preview shows headings, lists and links as readers will see them—especially on Git hosting where flavors differ slightly from generic Markdown.

Our Markdown preview runs in the browser for quick drafting: editor on one side, rendered HTML on the other so you spot broken emphasis or table alignment early.

Code fences deserve the same rigor as code

When docs include JSON, SQL or YAML samples:

• Paste JSON into JSON formatter and JSON validator so examples actually parse.
• For SQL excerpts, align casing with SQL formatter so newcomers copy something that runs.
• When samples show YAML config, round-trip through YAML ⇄ JSON if readers expect both shapes.

That discipline matters because bad samples erode trust faster than missing prose.

Connect docs work to distribution

Clear docs support onboarding and organic discovery when exported to blogs or help centers. Skill trends shows which stacks gain employer mentions; Blog is where long-form guides live next to utilities. Methodology for any data claims stays under Methodology.

Frequently asked questions

Should internal docs use Markdown?
Markdown wins for version-controlled prose next to code: diffs stay readable and generators can publish to sites or wikis.

How do I catch broken code samples?
Copy fenced JSON through formatter and validator paths; for SQL use SQL playground or SQL formatter before readers paste broken snippets.

Does preview replace a style guide?
No. Preview catches syntax; editorial standards still govern tone, heading hierarchy and link hygiene.

Doc workflow in practice

Headings, anchors and cross-links

Readers skim README files on Git hosting sites before they clone—heading hierarchy matters for auto-generated TOCs and deep links. Prefer one H1 or demote extra titles so anchors stay predictable. When you reference internal paths use repo-relative links in Markdown and absolute URLs only when the doc ships outside the repo. Broken relative links break trust faster than weak prose.

Fenced code and copy-paste ergonomics

Language tags on fences unlock syntax highlighting and help accessibility tooling; omitting them signals laziness. Include complete runnable snippets when possible—partial fragments force readers to invent imports or environment variables. For JSON samples pair JSON formatter with JSON validator in your own workflow before you paste examples into docs so readers never inherit typos.

Review rhythm that matches code

Treat documentation PRs like feature PRs: assign a reviewer who did not write the steps, run preview on every change and note what you verified in the description (command names, expected output shape). Link Skill trends when README guidance connects to hiring demand and Methodology when you cite external benchmarks beside setup instructions.

Diagrams, screenshots and maintenance burden

Explanatory images help onboarding until they rot—date screenshots when UI moves faster than prose. Prefer text instructions that survive redesigns; use images for topology or sequence where words sprawl. Alt text matters for accessibility and for teammates on slow connections—describe what the reader should conclude from the figure.

Templates for repeatable projects

Starter README templates accelerate teams—still customize sections so newcomers see real commands instead of placeholders. Link utilities consistently: JSON formatter for payload examples, SQL formatter for query excerpts. Consistency beats novelty when dozens of repos share expectations.

Changelogs adjacent to README updates

When behavior shifts update both code and the intro doc in one PR so issue trackers stay trustworthy. A README that references removed flags breeds distrust faster than no README—delete stale sections aggressively.

Accessibility beyond alt text

Semantic heading order helps screen readers navigate long README files—do not jump from # to ### because it looked prettier in preview. Link text should describe destinations (“see install steps”) instead of naked URLs scattered mid sentence. Those habits pair with Skill trends when documentation quality increasingly shows up in senior IC expectations.

Bottom line

Treat Markdown like interface code: preview often, validate fenced payloads and ship docs readers can run without guessing.