20241118 docs (#2629)

* module docs

* varbuilder gguf docs

* add a link to gguf files

* small additonal mod doc titles

* safetensor docs

* more core docs

* more module docs in canlde_core

* 2 more link fixes

candle-core/src/cuda_backend/mod.rs

@@ -1,3 +1,5 @@
+//! Implementation of Backend traits for CUDA device
+//!
 use crate::backend::{BackendDevice, BackendStorage};
 use crate::op::{BinaryOpT, CmpOp, ReduceOp, UnaryOpT};
 use crate::{CpuStorage, DType, Layout, Result, Shape, WithDType};