Update samba.md to allow writes

[neilh10]

As written it didn't work for me on the latest rasberrian/RaspberryPi3. Without the user share chmod it forbids access, and then with the specified samba uses nobody

[neilh10]

Thanks for looking at it. I've just noticed this conversation.

[ghost]

This PR makes the shared directory read/write by all users, including guest. I don't think this was the intention of the instructions as they were originally written. I read it as showing how to configure the share so that only the pi user can connect to it, however it was missing the step where you add the Samba password using smbpasswd. You should not need the chmod part if you do the smbpasswd correctly, then use the correct username and password to connect to the Samba share.

Also, you don't need both read only = no and writable = yes - they have the exact same meaning.

[aallan]

In light of #1911 and the lack of progress in a long while I'm marking this PR as 7 day closure.