The `Fetch` is an enum, not a struct, and "Type" probably makes more
sense here. Slightly reword the "generic" to not be confused with
generics.
Also fix the link to Tvixbolt, which got eaten by the line wrapping.
Change-Id: I677229f0365523620a640c2333e76790573f7318
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12174
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: Ilan Joselevich <personal@ilanjoselevich.com>
Tested-by: BuildkiteCI
3ea69235a4