usage example; pool close instead of gather

usage/USAGE.md

@@ -0,0 +1,80 @@
+# Using `asyncio-taskpool`
+
+## Simple example
+
+The minimum required setup is a "worker" coroutine function that can do something asynchronously, a main coroutine function that sets up the `TaskPool` and starts/stops the tasks as desired, eventually awaiting them all. 
+
+The following demo code enables full log output first for additional clarity. It is complete and should work as is.
+
+### Code
+```python
+import logging
+import asyncio
+
+from asyncio_taskpool.pool import TaskPool
+
+
+logging.getLogger().setLevel(logging.NOTSET)
+logging.getLogger('asyncio_taskpool').addHandler(logging.StreamHandler())
+
+
+async def work(n: int) -> None:
+    """
+    Pseudo-worker function. 
+    Counts up to an integer with a second of sleep before each iteration.
+    In a real-world use case, a worker function should probably have access 
+    to some synchronisation primitive or shared resource to distribute work 
+    between an arbitrary number of workers.
+    """
+    for i in range(n):
+        await asyncio.sleep(1)
+        print("did", i)
+
+
+async def main() -> None:
+    pool = TaskPool(work, (5,))  # initializes the pool; no work is being done yet
+    pool.start(3)  # launches work tasks 0, 1, and 2
+    await asyncio.sleep(1.5)  # lets the tasks work for a bit
+    pool.start()  # launches work task 3
+    await asyncio.sleep(1.5)  # lets the tasks work for a bit
+    pool.stop(2)  # cancels tasks 3 and 2
+    await pool.close()  # awaits all tasks, then flushes the pool
+
+
+if __name__ == '__main__':
+    asyncio.run(main())
+```
+
+### Output 
+Additional comments indicated with `<--`
+```
+Started work_pool_task_0
+Started work_pool_task_1
+Started work_pool_task_2
+did 0
+did 0
+did 0
+Started work_pool_task_3
+did 1
+did 1
+did 1
+did 0    <-- notice that the newly created task begins counting at 0 
+did 2
+did 2    <-- two taks were stopped; only tasks 0 and 1 continue "working"
+Cancelling work_pool_task_2 ...
+Cancelled work_pool_task_2
+Exiting work_pool_task_2
+Cancelling work_pool_task_3 ...
+Cancelled work_pool_task_3
+Exiting work_pool_task_3
+did 3
+did 3
+Exiting work_pool_task_0
+Exiting work_pool_task_1
+did 4
+did 4
+```
+
+## Advanced example
+
+...

usage/example_server.py

@@ -56,7 +56,7 @@ async def main() -> None:
     # Finally we allow for all tasks to do do their cleanup, if they need to do any, upon being cancelled.
     # We block until they all return or raise an exception, but since we are not interested in any of their exceptions,
     # we just silently collect their exceptions along with their return values.
-    await pool.gather(return_exceptions=True)
+    await pool.close(return_exceptions=True)
     await control_server_task