This commit adds a preset for llama.vim to use the default Qwen 2.5
Coder models.
The motivation for this change is to make it easier to start a server
suitable to be used with the llama.vim plugin. For example, the server
can be started with a command like the following:
```console
$ llama.vim --fim-qwen-1.5b-default
```
Refs: https://github.com/ggml-org/llama.cpp/issues/10932
d07c621393