feat(crawl): add subdomain and tld crawling

[j-mendez]

• add subdomain crawling ability
• add tld crawling ability

Collectively allows for gathering all pages that relate to a website bare host name with all . or tld extenstion or subdomains without sacrificing speed on crawl.

use spider::website::Website;
fn main() {
  let mut website: Website = Website::new("https://a11ywatch.com"); 
  website.configuration.subdomains = true;
  website.configuration.tld = true;
  website.crawl();
}

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Examples of output to validate since current test cases / examples do not use subdomains.

Before 25 links on the domain a11ywatch.com -

After 50+ links on the domain a11ywatch.com -

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This pr combines two features into one - subdomains and tld ignoring. It might make sense moving tld to a different variable and option since anyone can own a tld thats not attached to the exact hostname. You can use the combination of blacklist url to ignore certain tld extensions. Example - you can own myspace.com and someone else has the domain for myspace.net.