Auto-generate distro yamls + docs (#468)

# What does this PR do?

Automatically generates
- build.yaml
- run.yaml
- run-with-safety.yaml
- parts of markdown docs

for the distributions.

## Test Plan

At this point, this only updates the YAMLs and the docs. Some testing
(especially with ollama and vllm) has been performed but needs to be
much more tested.

llama_stack/templates/tgi/build.yaml

@@ -1,12 +1,19 @@
+version: '2'
 name: tgi
 distribution_spec:
-  description: Use TGI for running LLM inference
+  description: Use (an external) TGI server for running LLM inference
+  docker_image: llamastack/distribution-tgi:test-0.0.52rc3
   providers:
-    inference: remote::tgi
+    inference:
+    - remote::tgi
     memory:
     - inline::faiss
     - remote::chromadb
     - remote::pgvector
-    safety: inline::llama-guard
-    agents: inline::meta-reference
-    telemetry: inline::meta-reference
+    safety:
+    - inline::llama-guard
+    agents:
+    - inline::meta-reference
+    telemetry:
+    - inline::meta-reference
+image_type: conda