Fix README.md change devices() -> device_list()

[ScriptHound]

README.md tells me that to list all the devices connected i have to adb.devices(). But this raises an erorr:

adb.devices()
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
Input In [3], in <cell line: 1>()
----> 1 adb.devices()

AttributeError: 'AdbClient' object has no attribute 'devices'

I've tried help(adb) and found device_list method, which listed all the devices connected. So, I suggest updating README.md https://github.com/openatx/adbutils#list-all-the-devices-and-get-device-object

[stavis-dev]

I got with the same problem. Made a pull request. Waiting for acceptance. pull request