Add type definitions to package.json

Added "types" field pointing to "dist/index.d.ts" in package.json to include type definitions in the package. This change helps consumers of the package who are using TypeScript, providing them with autocompletion and type checking. Incremented package version from 1.2.5 to 1.2.6 to reflect this addition.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "code-tokenizer-md",
-  "version": "1.2.5",
+  "version": "1.2.6",
   "type": "module",
   "license": "AGPL-3.0-or-later",
   "repository": "https://github.com/geoffsee/code-tokenizer-md.git",
@@ -20,6 +20,7 @@
   "files": [
     "dist"
   ],
+  "types": "dist/index.d.ts",
   "scripts": {
     "build": "rm -rf dist && bun build ./src/index.ts ./src/cli.ts --splitting --outdir dist --target node && bun ./build.ts",
     "test": "bun test",