Add data components 151-175; clear MyGo row highlights

Lists, tables, trees, grids, inventories and records in data/.
Outline and GridView build on ui.List: ui.Outline strokes its arrows
and ui.GridView spaces and tints items. The pixel theme keeps MyGo's
row highlights clear so scrolled rows stay on whole dots; off lists
take a veil against the wheel. Adds Canvas.Silhouette, SwitchOptions
Label and exports Rarity.Slot.

data/descriptionlist.go

@@ -0,0 +1,29 @@
+package data
+
+import (
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/text"
+)
+
+type DescriptionListOptions struct {
+	// TermWidth is the terms' column in dots; zero means 80.
+	TermWidth int
+}
+
+// DescriptionList sets terms beside their descriptions.
+func DescriptionList(c *ui.Context, pairs [][2]string, o DescriptionListOptions) *ui.Element {
+	k := pixel.K(c)
+	tw := pixel.Or("DescriptionList TermWidth", o.TermWidth, 80)
+	return ui.Column(c).FillWidth().Gap(k.D(4)).Children(func() {
+		for _, p := range pairs {
+			ui.Row(c).FillWidth().Gap(k.D(8)).Children(func() {
+				ui.Box(c).Width(k.D(tw)).Shrink(0).Children(func() {
+					text.Paragraph(c, p[0], text.ParagraphOptions{Slot: pixel.Faint})
+				})
+				ui.Column(c).Grow(1).Children(func() { text.Paragraph(c, p[1], text.ParagraphOptions{}) })
+			})
+		}
+	})
+}