Address review: move plotting section, remove repeated fetch, add optional comment

Signed-off-by: Mathias L. Baumann <mathias.baumann@frequenz.com>

Author: Marenz

README.md

@@ -200,59 +200,51 @@ df = pd.DataFrame(data)
 print(df)
 ```
 
-## Command line client tool
-
-The package contains a command-line tool that can be used to request
-microgrid component data from the reporting API.
-
-```bash
-reporting-cli \
-    --url localhost:4711 \
-    --auth_key=$AUTH_KEY
-    --sign_secret=$SIGN_SECRET
-    --mid 42 \
-    --cid 23 \
-    --metrics AC_ACTIVE_POWER AC_REACTIVE_POWER \
-    --start 2024-05-01T00:00:00 \
-    --end 2024-05-02T00:00:00 \
-    --format csv \
-    --states \
-    --bounds
-```
-In addition to the default CSV format, individual samples can also be output using the `--format iter` option.
-
 ## Plotting data with matplotlib
 
 ```bash
 pip install matplotlib
 ```
 
+Using the `data` variable from any of the examples above:
+
 ```python
 import matplotlib.pyplot as plt
 import matplotlib.dates as mdates
 
-# Fetch data (see examples above)
-data = [
-    sample async for sample in
-    client.receive_single_component_data(
-        microgrid_id=1,
-        component_id=100,
-        metrics=[Metric.AC_ACTIVE_POWER],
-        start_time=datetime.fromisoformat("2024-05-01T00:00:00"),
-        end_time=datetime.fromisoformat("2024-05-02T00:00:00"),
-        resampling_period=timedelta(seconds=60),
-    )
-]
-
 timestamps = [s.timestamp for s in data]
 values = [s.value for s in data]
 
 fig, ax = plt.subplots(figsize=(14, 5))
 ax.plot(timestamps, values)
+
+# Optional: customize the plot
 ax.set_title("AC Active Power")
 ax.set_ylabel("Power (W)")
 ax.xaxis.set_major_formatter(mdates.DateFormatter("%H:%M"))
 ax.grid(True)
 fig.tight_layout()
+
 plt.show()
 ```
+
+## Command line client tool
+
+The package contains a command-line tool that can be used to request
+microgrid component data from the reporting API.
+
+```bash
+reporting-cli \
+    --url localhost:4711 \
+    --auth_key=$AUTH_KEY
+    --sign_secret=$SIGN_SECRET
+    --mid 42 \
+    --cid 23 \
+    --metrics AC_ACTIVE_POWER AC_REACTIVE_POWER \
+    --start 2024-05-01T00:00:00 \
+    --end 2024-05-02T00:00:00 \
+    --format csv \
+    --states \
+    --bounds
+```
+In addition to the default CSV format, individual samples can also be output using the `--format iter` option.