Add WebCrawler API

[n10ty]

Hi. Thanks for maintaining this big list. I would like to add WebCrawler API here.

• [x] Search previous suggestions before making a new one, as yours may be a duplicate.
• [x] Make an individual pull request for each suggestion.
• [x] Titles should be capitalized.
• [x] Keep descriptions short and simple.
• [x] End all descriptions with a full stop/period.
• [x] Check your spelling and grammar.
• [x] Make sure your text editor is set to remove trailing whitespace.
• [x] Try to make your Pull request and title as descriptive as possible.
• [x] Mark open source APIs with the open source icon
• [x] Mark all trial/demo based APIs with the 💸 emoticon.
• [x] Keep the APIs sorted alphabetically.
• [x] Whenever possible link directly to the documentation page!