Default examples counting against free quota

Based on issue raised by u/[oconnor663](https://www.reddit.com/r/rust/comments/1siifzc/comment/ofmtvoa/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button)
changed to default 20 per day as cap  for api usage 
Need to fix that default examples shouldn't considered while counting. 