update vocab.json for twi language

refined vocab.json for improved conciseness, removing numerals as MMS models struggle with accurate transcription.

vocab.json

@@ -1,32 +1,29 @@
 {
-  " ": 8,
-  "'": 5,
-  "-": 3,
-  "2": 23,
-  "3": 7,
-  "_": 6,
-  "a": 0,
-  "b": 29,
-  "d": 28,
-  "e": 24,
-  "f": 15,
-  "g": 17,
-  "h": 20,
-  "i": 26,
-  "k": 19,
-  "l": 21,
-  "m": 10,
-  "n": 4,
-  "o": 16,
-  "p": 9,
-  "r": 25,
-  "s": 22,
-  "t": 2,
-  "u": 18,
-  "w": 12,
-  "y": 13,
-  "á": 11,
-  "ɔ": 27,
-  "ɛ": 14,
-  "ʼ": 1
-}
+  "'": 1,
+  "[PAD]": 26,
+  "[UNK]": 25,
+  "a": 2,
+  "b": 3,
+  "d": 4,
+  "e": 5,
+  "f": 6,
+  "g": 7,
+  "h": 8,
+  "i": 9,
+  "k": 10,
+  "l": 11,
+  "m": 12,
+  "n": 13,
+  "o": 14,
+  "p": 15,
+  "r": 16,
+  "s": 17,
+  "t": 18,
+  "u": 19,
+  "w": 20,
+  "y": 21,
+  "|": 0,
+  "ɔ": 22,
+  "ɛ": 23,
+  "ʼ": 24
+}