[Windows] rustup-init.exe's on-screen instructions could be better

I wanted to install rust in order to do cargo install <various-tools>. I see few issues here when gettings started:

1. The on-screen instructions talk about version 2015 but the site where one should download says 2017. This confused me while searching for the right version:
   

2. The site where one downloads is full of text and clutter and various download options. Took me a few moments to read the page and find the right software to download and install.

3. Then I tried ruseup-init.exe again, but it still complained about about missing C++ build tools. Turns out that the software bundle installed in step 2 does not by default install the C++ build tools. So back to the Build Tools for Visual Studio 2017 and checking the right extra checkbox and reinstall.

Step 2 and 3 take about 2-3 hours and lots of disk space.

Actionable things that could be better here to improve Onboarding:

1. Chance on-screen instructions to refer to 2017 and not the 2015 version.
2. Maybe add a html guide with screenshots showing which software to download and which checkboxes to hit while installing. Or even better a GUI installer with screenshots.
3. Also tell the user in the guide that it might take some time and also how much space it will take up on the hard drive.

Related to #1122.

PS As a side note I already tried to install some weeks ago and stopped at step 2 then noticing that I had not enought disk space.

Start with the Windows rustup-init.exe onboarding instructions and read related issue #1122 for context. Update the guidance to refer to Visual Studio 2017, explain the required C++ build tools and installation choices, and note expected time and disk usage; a suitable guide or installer experience should make these steps clear.