added README

gallery/readme_banner.typ

@@ -0,0 +1,50 @@
+#import "/src/lib.typ": *
+
+#let dark = sys.inputs.at("dark", default: "false") == "true"
+
+#set page(
+  width: auto,
+  height: auto,
+  margin: 1cm,
+  fill: none
+)
+
+#set text(
+  size: 12pt,
+  font: "Source Sans 3",
+  fill: if dark {white} else {black}
+)
+
+#let hex-abc = "0123456789abcdef"
+#let g = gradient.linear(
+  red,
+  orange,
+  yellow,
+  green,
+  aqua,
+  blue,
+  purple
+)
+#let colorize-hex(txt) = {
+  let chars = txt.clusters().map(c => {
+    let v = hex-abc.position(c)
+    let color = g.sample(v * 100% / 15).lighten(20%).desaturate(40%)
+    box(
+      fill: color,
+      inset: (x: 1pt),
+      outset: (
+        top: 1pt + 0.5pt * v,
+        bottom: 1pt + 0.5pt * v
+      ),
+      raw(c)
+    )
+  })
+
+  set text(fill: black)
+  chars.join()
+}
+
+#let txt = "Jumble"
+#let cipher = bytes-to-hex(sha1(txt))
+
+*sha1("#txt") =* #colorize-hex(cipher)