Drop --token from the hand-started worker examples

The worker reads FLUKSIO_WORKER_TOKEN itself; on the command line the
token shows in ps. The --token row in the options table says so.

docs/getting-started/data-science.md

@@ -161,11 +161,10 @@ nothing of yours, so a container is always this case.
 
     `pip install fluksio-worker` into the environment the training code runs
     in, and node code runs on it: `--python` defaults to the interpreter the
-    agent was started with.
+    agent was started with. It reads its token from `FLUKSIO_WORKER_TOKEN`.
 
     ```sh
-    fluksio worker --url ws://127.0.0.1:8000/api/v1/workers/attach \
-      --token "$WORKER_TOKEN" --labels gpu
+    fluksio worker --url ws://127.0.0.1:8000/api/v1/workers/attach --labels gpu
     ```
 
     Then give the node `device="gpu"`; see [Remote workers](../code/workers.md).
@@ -469,7 +468,7 @@ alongside the store's own. `--dry-run` prints all of this and uploads nothing;
 
     ```sh
     fluksio worker --url ws://127.0.0.1:8000/api/v1/workers/attach \
-      --token "$WORKER_TOKEN" --labels local --python "$(which python)"
+      --labels local --python "$(which python)"
     ```
 
     Then give the node `device="local"`.

docs/getting-started/facility-automation.md

@@ -258,13 +258,12 @@ curl -X POST https://api.${DOMAIN}/api/v1/workers/tokens \
 The labels are signed into it, so the worker can repeat them with `--labels`
 but not change them.
 
-On the other machine:
+On the other machine, with that token in `FLUKSIO_WORKER_TOKEN`:
 
 ```sh
 pip install fluksio-worker
 fluksio-worker \
   --url wss://api.${DOMAIN}/api/v1/workers/attach \
-  --token "$WORKER_TOKEN" \
   --labels shed,gpio \
   --parallel 2
 ```