Do not assume working from $HOME

In the "Yocto Project Quick Build" instructions
(https://docs.yoctoproject.org/brief-yoctoprojectqs/index.html#)
there is an inconsistency that impacts several documents...

People are first instructed to clone the poky git repository, but not
mentioning from which directory. Then, it's consistent to instruct
people to run "cd poky/".

However, later in the instructions, readers are instructed to run "cd
~/poky", which assumes that cloning poky was done from the home
directory. Many other places in the documentation make such an assumption.

This change fixes this, and makes no assumption on where people
have chosen to store their data, in particular where they cloned
the "poky" repository.

This also fixes a few whitespace issues.

(From yocto-docs rev: fd4e365c85df212d7ed70fc1abb3657a4a88b294)

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/README

@@ -222,7 +222,7 @@ For example, the following .rst content will produce the 'expected'
 content:
 
   .. code-block::
-      $ mkdir ~/poky-&DISTRO;
+      $ mkdir poky-&DISTRO;
       or
       $ git clone &YOCTO_GIT_URL;/git/poky -b &DISTRO_NAME_NO_CAP;