Drop `\b` around the default lexeme regexp
Drop `\b` around the default lexeme regexp

`\w+` already implies that it is surrounded by a word limit. Tests
pass so there are probably no weird side effects.

palmin/highlight.js,sourrust/highlight.js,highlightjs/highlight.js,highlightjs/highlight.js,MakeNowJust/highlight.js,aurusov/highlight.js,palmin/highlight.js,carlokok/highlight.js,teambition/highlight.js,carlokok/highlight.js,bluepichu/highlight.js,MakeNowJust/highlight.js,StanislawSwierc/highlight.js,bluepichu/highlight.js,isagalaev/highlight.js,carlokok/highlight.js,lead-auth/highlight.js,highlightjs/highlight.js,Sannis/highlight.js,highlightjs/highlight.js,Sannis/highlight.js,bluepichu/highlight.js,Sannis/highlight.js,StanislawSwierc/highlight.js,teambition/highlight.js,sourrust/highlight.js,isagalaev/highlight.js,palmin/highlight.js,carlokok/highlight.js,sourrust/highlight.js,teambition/highlight.js,aurusov/highlight.js,MakeNowJust/highlight.js,aurusov/highlight.js