update README, improved sample (in preparation for demo)

sample-old.py

@@ -0,0 +1,69 @@
+import json
+import panel
+from random import randint
+from typing import Any
+
+from watt42_viewlib import attach_w42_state
+
+w42_state = panel.rx(None)
+attach_w42_state(rx_var=w42_state, system_id="fb2b91ce-383e-4356-96b3-b6405dacb353")
+
+state_as_text = panel.bind(lambda s: f"W42 State:\n\n```\n{json.dumps(s, indent=2)}\n```\n\nReplace this with some awesome visuals", w42_state)
+
+state_pane = panel.pane.Markdown(state_as_text, sizing_mode='stretch_width')
+
+value = w42_state.rx.value
+
+multiplier = panel.widgets.IntSlider(name='Multiplier', start=1, end=10, step=1, value=1)
+
+def value_display(state: dict[str, Any], multiplier: int) -> str:
+    if state and 'value' in state:
+        return f"Current W42 State Value times multiplier: {state['value'] * multiplier}"
+    return "Current W42 State Value: N/A"
+
+def value_or_zero(state: dict[str, Any]) -> int:
+    if state and 'value' in state:
+        return state['value']
+    return 0
+
+def array_from_value(x: int) -> list[int]:
+    return [x * randint(1, 20) for _ in range(25)]
+
+def times2(x: int) -> int:
+    return x * 2
+
+times2_rx = panel.rx(times2)(panel.rx(value_or_zero)(w42_state))
+
+markdown_rx = panel.rx(lambda v: f"## Value times 2 is: {v}, array={array_from_value(v)}")(times2_rx)
+
+array_rx = panel.rx(array_from_value)(panel.rx(value_or_zero)(w42_state))
+
+echart_bar_rx = panel.pane.ECharts(
+    panel.rx(lambda arr: {
+        'xAxis': {
+            'type': 'category',
+            'data': [f'Item {i+1}' for i in range(len(arr))]
+        },
+        'yAxis': {
+            'type': 'value'
+        },
+        'series': [{
+            'data': arr,
+            'type': 'bar'
+        }]
+    })(array_rx),
+    sizing_mode='stretch_width',
+    height=400
+)
+
+_ = panel.template.FastListTemplate(
+    title="Sample W42 View App",
+    sidebar=[panel.pane.Markdown("This is a sample sidebar.")],
+    main=[
+        panel.pane.Markdown("# Welcome to the Main Content Area"),
+        echart_bar_rx,
+        # state_pane, panel.pane.Markdown(f"Current W42 State Value: {value}"),
+        panel.ReactiveExpr(panel.rx(value_display)(w42_state, multiplier), widget_location='top'),
+        panel.pane.Markdown(markdown_rx),
+    ],
+).servable()