Document llmman and rename OLLAMA_IP/PORT to LLM_ENDPOINT/PORT (#198)

llmman (https://github.com/llmmanorg/llmman) serves the Ollama API on
port 17434 and works with the bot as-is, so document it in setup-local
and link it from the README. Since the backend is no longer Ollama-only,
rename the env vars to LLM_ENDPOINT / LLM_PORT as requested in review.
OLLAMA_IP / OLLAMA_PORT are kept as deprecated aliases in keys.ts and
docker-compose.yml so existing deployments keep working.

docker-compose.yml

@@ -10,8 +10,8 @@ services:
     image: kevinthedang/discord-ollama:0.9.1
     environment:
       CLIENT_TOKEN: ${CLIENT_TOKEN}
-      OLLAMA_IP: ${OLLAMA_IP}
-      OLLAMA_PORT: ${OLLAMA_PORT}
+      LLM_ENDPOINT: ${LLM_ENDPOINT:-${OLLAMA_IP}}     # OLLAMA_IP is a deprecated alias
+      LLM_PORT: ${LLM_PORT:-${OLLAMA_PORT}}           # OLLAMA_PORT is a deprecated alias
       MODEL: ${MODEL}
     networks:
       ollama-net:
@@ -26,14 +26,14 @@ services:
     restart: always
     networks:
       ollama-net:
-        ipv4_address: ${OLLAMA_IP}
+        ipv4_address: ${LLM_ENDPOINT:-${OLLAMA_IP}}
     runtime: nvidia             # use Nvidia Container Toolkit for GPU support
     devices:
       - /dev/nvidia0
     volumes:
       - ollama:/root/.ollama
     ports: 
-      - ${OLLAMA_PORT}:${OLLAMA_PORT}
+      - ${LLM_PORT:-${OLLAMA_PORT}}:${LLM_PORT:-${OLLAMA_PORT}}
 
 # create a network that supports giving addresses withing a specific subnet
 networks: