Support space as seperator between language and additional class in c…

[tuyen-at-work]

…ode block

This PR try to resolve this issue: #1384

[ehuss]

Thanks! It looks like rustdoc will be making a similar change (rust-lang/rust#78429). Maybe this should match its behavior and also support the tab character? (I don't think it should bother with the curly brace issue.)
Unfortunately, per rust-lang/rust#78429 (comment), it doesn't seem like there is much agreement on how this should work, but spaces and tabs seem reasonable. I'd also like to wait until the rustdoc changes land.

[tuyen-at-work]

@ehuss as your comment, GitHub supports ,, space and \t. VS Code supports space and \t but not ,. They are the biggest guys in the market. So I think it is most flexible to support all 3 chars, like GitHub does. I think as long as GitHub supports it, other implementation will follow suits.

[jyn514]

Thanks! It looks like rustdoc will be making a similar change (rust-lang/rust#78429). Maybe this should match its behavior and also support the tab character?

Just to clarify - rustdoc already splits on spaces (in fact, it splits on almost anything that's not a letter). rust-lang/rust#78429 is removing delimiters, not adding more.

[ehuss]

I went ahead and pushed a change to add tab to be consistent with rustdoc and GitHub.