Use unicode compat slug engine

vendor/github.com/rainycape/unidecode/unidecode.go

@@ -0,0 +1,58 @@
+// Package unidecode implements a unicode transliterator
+// which replaces non-ASCII characters with their ASCII
+// approximations.
+package unidecode
+
+//go:generate go run make_table.go
+
+import (
+	"sync"
+	"unicode"
+)
+
+const pooledCapacity = 64
+
+var (
+	slicePool    sync.Pool
+	decodingOnce sync.Once
+)
+
+// Unidecode implements a unicode transliterator, which
+// replaces non-ASCII characters with their ASCII
+// counterparts.
+// Given an unicode encoded string, returns
+// another string with non-ASCII characters replaced
+// with their closest ASCII counterparts.
+// e.g. Unicode("áéíóú") => "aeiou"
+func Unidecode(s string) string {
+	decodingOnce.Do(decodeTransliterations)
+	l := len(s)
+	var r []rune
+	if l > pooledCapacity {
+		r = make([]rune, 0, len(s))
+	} else {
+		if x := slicePool.Get(); x != nil {
+			r = x.([]rune)[:0]
+		} else {
+			r = make([]rune, 0, pooledCapacity)
+		}
+	}
+	for _, c := range s {
+		if c <= unicode.MaxASCII {
+			r = append(r, c)
+			continue
+		}
+		if c > unicode.MaxRune || c > transCount {
+			/* Ignore reserved chars */
+			continue
+		}
+		if d := transliterations[c]; d != nil {
+			r = append(r, d...)
+		}
+	}
+	res := string(r)
+	if l <= pooledCapacity {
+		slicePool.Put(r)
+	}
+	return res
+}