docs feature codeblock hyphenated lang regex

[ghostdevv]

Handle hyphenated fenced languages in @example blocks.

These regexes only consume \w, so a valid fence like ```glimmer-ts is parsed as language glimmer and leaves -ts at the start of the code body. That breaks example rendering for some Shiki languages now loaded in server/utils/shiki.ts, instead of falling back cleanly.

Originally posted by @coderabbitai[bot] in #2382 (comment)