Fix typo in feedspec
Add products_search in requests.yml and their recordings
Document new apiv3 endpoint GET /shops/:shop_id/products/search{?shop_uid}
Merge remote-tracking branch 'origin/apiv3/product_search'
Add Changelog entry in APIv3 sidebar
Add APIv3 changelog content
Merge remote-tracking branch 'origin/changelog'
Fix typo in API FAQ
Move API v3 changelog entry next to overview
Make more OAuth2.0 APIv3 requirement more prominent

* Also mention that we no longer issue new keys for APIv2.