* refactor(search): avoid issue with one character keyword
closes https://github.com/CaiJimmy/hugo-theme-stack/issues/184
* Remove keyword sorts
* fix typo: secion -> section
* fix(search): avoid matching html entity
* Use | operator to concatenate keywords
Idea from https://github.com/CaiJimmy/hugo-theme-stack/pull/436
* Add missing `matchCount`
* Limit preview length
* Don't add ellipsis to title
* add comment to `processMatches`
* Initialize DOMParser only once
* Remove marker function
* Deal with blank search
* Use const keyword for constant arrays
