Make default self closing tags case sensitive

[MarcPorciuncula]

Many modern web frameworks disambiguate their own custom tags from native html tags by capitalising the name of the tag. For example, I am using React and Next.js, which exposes a Link component. When I try to autocomplete a Link tag, it is registered by less-than-slash as a self closing link tag and ignored, usually giving me an incorrect completion.

Making tag matching case sensitive will fix this issue.