Create a post search component

[zhenyanghua]

Such component should allow users to type to search post by title:

• type ahead by title (min 3 chars)
• On select go to the article
• A11y support
• Create type ahead data at build time and store as JSON
• Fetch the JSON and store locally after user types 2 chars, when storing the JSON, the date for storing needs to be stamped so that next time when getting from local storage, it may be invalidated if it is older than 4 hours.