Feature propose: Make whole search result area clickable

[laysent]

Hi, I would like to propose a change to search plugin. Currently, only the title of search result is clickable. It might sound a bit weird for users as the search content is plain text and cannot redirect them.

This PR will make the complete area clickable by wrapping the whole area with a tag.

One thing to notice is that the search keyword will be rendered using theme color, the same color when mouse hovered. To distinguish them, I made the keyword also bold.

How it looks when displaying search result:

How it looks when mouse hovered:

Should work fine with all default themes. But perhaps not a very well-designed. Let me know if you have any feedback.

Please makes sure these boxes are checked before submitting your PR, thank you!

• Make sure you are merging your commits to master branch.
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• DO NOT include files inside lib directory.