Add jekyll-algolia search

[0xdevalias]

• https://github.com/algolia/jekyll-algolia
• https://github.com/algolia/jekyll-algolia#more-about-the-community-plan
• https://github.com/algolia/jekyll-algolia-example
• https://www.algolia.com/pricing/
• https://community.algolia.com/jekyll-algolia/getting-started.html
• https://community.algolia.com/instantsearch.js/
• https://github.com/algolia/react-instantsearch
• https://www.algolia.com/doc/guides/building-search-ui/what-is-instantsearch/react/
• https://community.algolia.com/docsearch/run-your-own.html
  • https://github.com/algolia/docsearch
  • https://github.com/algolia/docsearch-scraper