Fix exports in gitbook/expr package.json after removing src (#3648)

Author: spastorelli

.changeset/hungry-cars-play.md

@@ -0,0 +1,5 @@
+---
+"@gitbook/expr": minor
+---
+
+Fix exports in gitbook/expr package.json

packages/expr/package.json

@@ -6,7 +6,7 @@
     "exports": {
         ".": {
             "types": "./dist/index.d.ts",
-            "development": "./src/index.ts",
+            "import": "./dist/index.js",
             "default": "./dist/index.js"
         }
     },