Updated enums per #434 (#671)

src/constants/PSM.js

@@ -15,4 +15,5 @@ module.exports = {
   SINGLE_CHAR: '10',
   SPARSE_TEXT: '11',
   SPARSE_TEXT_OSD: '12',
+  RAW_LINE: '13',
 };

src/index.d.ts

@@ -84,13 +84,13 @@ declare namespace Tesseract {
     width: number
     height: number
   }
-  const enum OEM {
+  enum OEM {
     TESSERACT_ONLY,
     LSTM_ONLY,
     TESSERACT_LSTM_COMBINED,
     DEFAULT,
   }
-  const enum PSM {
+  enum PSM {
     OSD_ONLY = '0',
     AUTO_OSD = '1',
     AUTO_ONLY = '2',