[Doc] Improve installation signposting (#12575)

- Make device tab names more explicit
- Add comprehensive list of devices to
https://docs.vllm.ai/en/latest/getting_started/installation/index.html
- Add `attention` blocks to the intro of all devices that don't have
pre-built wheels/images

---------

Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

docs/source/getting_started/installation/index.md

@@ -6,8 +6,23 @@ vLLM supports the following hardware platforms:
 
 :::{toctree}
 :maxdepth: 1
+:hidden:
 
 gpu/index
 cpu/index
 ai_accelerator/index
 :::
+
+- <project:gpu/index.md>
+  - NVIDIA CUDA
+  - AMD ROCm
+  - Intel XPU
+- <project:cpu/index.md>
+  - Intel/AMD x86
+  - ARM AArch64
+  - Apple silicon
+- <project:ai_accelerator/index.md>
+  - Google TPU
+  - Intel Gaudi
+  - AWS Neuron
+  - OpenVINO