routie dev init since i didn't adhere to any proper guidance up until now

frontend/node_modules/get-east-asian-width/utilities.js

@@ -0,0 +1,24 @@
+/**
+Binary search on a sorted flat array of [start, end] pairs.
+
+@param {number[]} ranges - Flat array of inclusive [start, end] range pairs, e.g. [0, 5, 10, 20].
+@param {number} codePoint - The value to search for.
+@returns {boolean} Whether the value falls within any of the ranges.
+*/
+export const isInRange = (ranges, codePoint) => {
+	let low = 0;
+	let high = Math.floor(ranges.length / 2) - 1;
+	while (low <= high) {
+		const mid = Math.floor((low + high) / 2);
+		const i = mid * 2;
+		if (codePoint < ranges[i]) {
+			high = mid - 1;
+		} else if (codePoint > ranges[i + 1]) {
+			low = mid + 1;
+		} else {
+			return true;
+		}
+	}
+
+	return false;
+};