chore: update README

Author: whitelisab

README.md

@@ -241,7 +241,7 @@ contentfulExport({
 })
 ```
 
-### Error: 400 - Bad Request - Response size too big.
+### Error: 400 - Bad Request - Response size too big
 
 Contentful response sizes are limited (find more info in our [technical limit docs](https://www.contentful.com/developers/docs/technical-limits/)). In order to resolve this issue, limit the amount of entities received within a single request by setting the [`maxAllowedLimit`](#maxallowedlimit-number-default-1000) option: