chore: rename templates to distributions (#3035)

As the title says. Distributions is in, Templates is out.

`llama stack build --template` --> `llama stack build --distro`. For
backward compatibility, the previous option is kept but results in a
warning.

Updated `server.py` to remove the "config_or_template" backward
compatibility since it has been a couple releases since that change.

docs/source/distributions/self_hosted_distro/dell.md

@@ -153,7 +153,7 @@ docker run \
   --pull always \
   -p $LLAMA_STACK_PORT:$LLAMA_STACK_PORT \
   -v $HOME/.llama:/root/.llama \
-  -v ./llama_stack/templates/tgi/run-with-safety.yaml:/root/my-run.yaml \
+  -v ./llama_stack/distributions/tgi/run-with-safety.yaml:/root/my-run.yaml \
   llamastack/distribution-dell \
   --config /root/my-run.yaml \
   --port $LLAMA_STACK_PORT \
@@ -169,7 +169,7 @@ docker run \
 Make sure you have done `pip install llama-stack` and have the Llama Stack CLI available.
 
 ```bash
-llama stack build --template dell --image-type venv
+llama stack build --distro dell --image-type venv
 llama stack run dell
   --port $LLAMA_STACK_PORT \
   --env INFERENCE_MODEL=$INFERENCE_MODEL \

docs/source/distributions/self_hosted_distro/meta-reference-gpu.md

@@ -109,7 +109,7 @@ docker run \
 Make sure you have done `uv pip install llama-stack` and have the Llama Stack CLI available.
 
 ```bash
-llama stack build --template meta-reference-gpu --image-type venv
+llama stack build --distro meta-reference-gpu --image-type venv
 llama stack run distributions/meta-reference-gpu/run.yaml \
   --port 8321 \
   --env INFERENCE_MODEL=meta-llama/Llama-3.2-3B-Instruct

docs/source/distributions/self_hosted_distro/nvidia.md

@@ -158,7 +158,7 @@ If you've set up your local development environment, you can also build the imag
 
 ```bash
 INFERENCE_MODEL=meta-llama/Llama-3.1-8b-Instruct
-llama stack build --template nvidia --image-type venv
+llama stack build --distro nvidia --image-type venv
 llama stack run ./run.yaml \
   --port 8321 \
   --env NVIDIA_API_KEY=$NVIDIA_API_KEY \

docs/source/distributions/self_hosted_distro/starter.md

@@ -169,7 +169,7 @@ docker run \
 Ensure you have configured the starter distribution using the environment variables explained above.
 
 ```bash
-uv run --with llama-stack llama stack build --template starter --image-type venv --run
+uv run --with llama-stack llama stack build --distro starter --image-type venv --run
 ```
 
 ## Example Usage