Added screenshots for python3 getting_started.py test step

[mwherman2000]

I've only tested this against the Windows 10 setup steps (previous section of the README.md).

The updated instructions and screen shots assume the python folder is here: /indy-dev/python. Is this the same on Mac and Linux?

[kdenhartog]

I'd like to remove all of the images that aren't currently being used to keep the size of this repository smaller. Did you have a plan to use these?

[mwherman2000]

It's a bit TBD for the unused images. As part of trying to figure out the getting_started.py script, I'm trying to correlate the major and minor steps/tasks in this script with:

• https://github.com/hyperledger/indy-sdk/blob/master/doc/getting-started/getting-started.md, and
• https://github.com/hyperledger/indy-sdk/blob/master/doc/getting-started/getting-started.svg

I'll likely end up have to regenerate the unused images ...so let me delete them for now.

[kdenhartog]

I've gotten a chance to look through this work. I think this is headed in the right direction. It looks like there's a few things that still have TODOs in there. Once you've gotten to a point where you feel like it's ready or you'd like another review can you ping me in the comments here or on rocketchat?