Initial: pi-skill — 68 skills, 43 extensions, 11 themes for Pi

skills/references/type-timeline.md

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+# Timeline
+
+**Best for:** release history, project milestones, incident timelines, roadmaps, changelog visualizations.
+
+## Layout conventions
+- Horizontal hairline baseline across the middle (`stroke-width=1`).
+- Tick marks at time boundaries (quarters, months, sprints) with date labels below in Geist Mono.
+- Events: small filled circles (`r=4`) on the baseline. Labels alternate above and below to prevent collision, connected to the circle with a 1px hairline drop.
+- Major milestones: coral circle (`r=6`) + bold Geist label.
+- Time scale must be honest: if intervals are non-equal, space the circles non-equally. Don't fake linear spacing for aesthetics. Break the axis visibly if a region is too dense.
+
+## Anti-patterns
+- Equal-spacing events that aren't equally spaced in time.
+- Missing axis labels ("what unit is this?").
+- Crowded labels without vertical offset — illegible.
+
+## Examples
+- `assets/example-timeline.html` — minimal light
+- `assets/example-timeline-dark.html` — minimal dark
+- `assets/example-timeline-full.html` — full editorial