XML schema mapping URL

[l3pp4rd]

Hi,
I'm the initial author of this source code and I see that you still have references in readme.md for the old XML
schema URLs to my local server in Lithuania http://gediminasm.org/schemas/orm/doctrine-extensions-mapping

Please change it to local github url, so the ones still using these, could migrate at some point.
I'm considering to shut down the server in few months or so.

[mbabker]

I think we just need to document a xsi:schemaLocation element since changing the URL, which is used as the XML namespace, would be a B/C break. So the docs and test fixtures would need to be updated to be something like this:

<doctrine-mapping xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping"
                  xmlns:gedmo="http://gediminasm.org/schemas/orm/doctrine-extensions-mapping"
                  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                  xsi:schemaLocation="http://doctrine-project.org/schemas/orm/doctrine-mapping https://www.doctrine-project.org/schemas/orm/doctrine-mapping.xsd
                                      http://gediminasm.org/schemas/orm/doctrine-extensions-mapping https://raw.githubusercontent.com/doctrine-extensions/DoctrineExtensions/refs/heads/main/schemas/orm/doctrine-extensions-mapping-2-2.xsd"
>
<!-- entity mapping -->
</doctrine-mapping>