Readme update

Author: neumond

README.md

@@ -52,3 +52,41 @@ async def program(api):
     # and this snippet takes approximately 2 seconds to complete.
     await asyncio.gather(api.os.sleep(2), api.os.sleep(2))
 ```
+
+Opening a file:
+
+```python
+async def program(api):
+    async with api.fs.open('filename', 'r') as f:
+        async for line in f:
+            await api.print(line)
+```
+
+Capturing event:
+
+```python
+async def program(api):
+    async with api.os.captureEvent('timer') as timer_event_queue:
+        timer_id = await api.os.startTimer(2)
+        async for etid, *_ in timer_event_queue:
+            if etid == timer_id:
+                  await api.print('Timer reached')
+                  break
+```
+
+Using modems:
+
+```python
+async def program(api):
+    modem = await api.peripheral.wrap('back')
+    listen_channel = 5
+    async with modem.receive(listen_channel) as q:
+        async for msg in q:
+            await api.print(repr(msg))
+            if msg.content == 'stop':
+                break
+            else:
+                await modem.transmit(msg.reply_channel, listen_channel, msg.content)
+```
+
+More examples can be found in `testmod.py`.

testmod.py

@@ -502,6 +502,9 @@ async def test_fs_api(api):
     async with api.fs.open('tdir/binfile', 'rb') as f:
         assert isinstance(await f.read(), int)
 
+    async with api.fs.open('tdir/binfile', 'r') as f:
+        assert [line async for line in f] == ['bbcccaaaaddd']
+
     assert await api.fs.delete('tdir') is None
     assert await api.fs.delete('tfile') is None
     assert await api.fs.delete('doesnotexist') is None