Refine the overview text

Attached is a screenshot of the current overview page.

1. Use consistent names for the source site and the destination site.
2. Should the doc link use the title of the destination page?
3. Is the term 'handbook' correct? Following the link I see documentation but nothing that indicates it is a 'handbook'. This is confusing.
4. That documentation page linked to is very high level, maybe need one more specific? For example, when I read it I thought I'd see a detailed example of using this. But I got a lot of high level stuff.

My attempt to share my thoughts on this:

Upgrade Drupal 6 or Drupal 7 (previous site) to Drupal 8 (this site).

To upgrade, complete the following.

    1. Make sure that the host this site is on has access to the database for your previous site.
    2. If your previous site has private files to be migrated, a copy of that files directory *must* be accessible to the host this site is on.
    3. Make sure any modules to upgrade are *enabled on both* the previous site and this site.
    4. Put this site into *maintenance* mode.
    5. Back up the database for this site. Upgrading *will* change the database for this site.

When you have performed the steps above, you may proceed.

For more detailed information, see "Upgrading to Drupal 8". If you are unsure how to setup the database or file access contact your hosting provider.

Ah, here it is. Linking to this is better, Upgrading from Drupal 6 or 7 to Drupal 8

Decided to make a patch so I see the changes in action. Then I noticed that #3 suggests, at least to me, that a module will be upgraded. So I tweaked that as well.

This still needs work as anyone reading this will see I am not a wordsmith.

I think it would be good to have a line that explains the basic concept of importing an existing site into a seperate, new clean install. Your intro already does this but maybe:

Upgrade a site to version 8 by importing it into this new installation. See the upgrading handbook for more detailed information.

Do we want to point out that you should start from a new clean d8 install?
Upgrade into a clean and empty new install of Drupal 8. You will probably lose any existing configuration once you import your site into it.

And that you probably don't want to import from production?
This upgrade can take a long time. It’s better to import a local copy of your site instead of directly importing from your live site.

I would like to get rid of the 'contact your hosting provider' bit, that should be part of the handbook, so that we only have to point to one next place to go for more information.