Updated: Moved extension internals into repostitory root

Hello,

In this pull request we have moved the extension internals into the repository root to make the checkout process work cleanly by default without extra work or symlinks.

Details
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We recently had the need to change content object class of over 1707 content objects.

We were pleased to find again your extension updated to work with the latest community release. The extension worked perfectly for us the first time!

We were however disappointed to find that the extension has not been touched since it's initial re-import.

We hope to help improve this with our first pull request!

We think that the extension internals belong in the repository root like almost every other ezpublish extension on GitHub (from eZ Systems, 3rd Party Vendors, Partners, Community Members, etc).

Closing
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We think this pull request is important to help people be able to make quick use of the extension without needing to move the extension checked out around. Please let us know what you think.

Thank you for your continued support!

Cheers,
Brookins Consulting