fix: highlight self as variable in JavaScript (fixes #4339)#4375

KJyang-0114 wants to merge 1 commit intohighlightjs:mainhighlightjs/highlight.js:mainfrom

KJyang-0114:fix/issue-4339-self-highlightKJyang-0114/highlight.js:fix/issue-4339-self-highlightCopy head branch name to clipboard