Remove unnecessary explicit title anchors and use relative links instead (#20620)

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

docs/contributing/model/basic.md

@@ -1,7 +1,6 @@
 ---
 title: Basic Model
 ---
-[](){ #new-model-basic }
 
 This guide walks you through the steps to implement a basic vLLM model.
 
@@ -108,7 +107,7 @@ This method should load the weights from the HuggingFace's checkpoint file and a
 
 ## 5. Register your model
 
-See [this page][new-model-registration] for instructions on how to register your new model to be used by vLLM.
+See [this page](registration.md) for instructions on how to register your new model to be used by vLLM.
 
 ## Frequently Asked Questions