Fix executable dir in + tabify pip & virtual envs guide

[ichard26]

Fixes #783.

This patch also completes the "tabification" this document.

[bhrutledge]

Thanks for this; I like seeing the adoption of tabs in this doc. I've got a few questions/suggestions.

[bhrutledge]

This is a very old version of pip and Python. Can we take the opportunity to show the latest version for Windows and Unix/macOS?

[bhrutledge]

Also, this is one of a few places in this document where the command and its output are shown in a single code-block, but with no distinction between them, which might lead folks to thinking that pip 9.0.1 ... is a command to execute.

If the output is valuable, I recommend putting into a separate code-block, maybe something like:

Suggested change

	pip 9.0.1 from c:\python36\lib\site-packages (Python 3.6.1)
	.. code-block:: text
	pip 9.0.1 from c:\python36\lib\site-packages (Python 3.6.1)

Again, we'd want to do the same for Unix/macOS, and similarly for the "You can confirm you're in the virtual environment" instructions. But that could also be a follow-up PR.

[ichard26]

I was avoiding any informational changes to the document since I was afraid I lack the domain knowledge to do them properly, but this seems reasonable and I like it! I think it's fine to include these changes (on a first glance) since this PR already makes significant visual changes.

[bhrutledge]

Actually, I think the fact this PR makes significant visual changes is reason enough to do this in a subsequent PR. Let's just fix the slashes (below) for now.

[bhrutledge]

I've created #931 as a follow-up.

[bhrutledge]

Thanks!

[henryiii]

There there a way to avoid the syntax highlighting doing this with the backslashes?

[henryiii]

I think you can use the .. code-block:: bat lexer. This problem happens on other pages, too (I think I used the wrong page for the screenshot above), not something to fix right now, but good idea for later. Created #934 for this.

[bhrutledge]

One more small tweak, based on @henryiii's observation.

[ichard26]

Thanks @henryiii, @pradyunsg and @bhrutledge for the reviews, it's well appreciated! 🙂

[bhrutledge]

@ichard26 Thank for the improvements! If you feel like doing more, #931 would be a good follow-up.