emoji: make the list an independent doc

during this draft phase, the authoritative document for the ordering of
the emoji needs to be consumable by other languages and as a library.

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

emoji/map.go

@@ -0,0 +1,9 @@
+//go:generate go run map_json.go
+
+package emoji
+
+// Map returns the emoji at the provided position.
+// This list is from 0-255
+func Map(b byte) string {
+	return sumList[int(b)]
+}