Build modified streamline images

The official image from streamline does not currently work for the arm64
platform. As a temporary measure, the source code and docker build scripts
have been lifted from the official images and are used to build locally.

Some additional modifications are made to reduce overall image size, these
are documented in docker/README.md

docker/streamline-src/vendor/symfony/routing/README.md

@@ -0,0 +1,66 @@
+Routing Component
+=================
+
+The Routing component maps an HTTP request to a set of configuration variables.
+
+Getting Started
+---------------
+
+```
+$ composer require symfony/routing
+```
+
+```php
+use App\Controller\BlogController;
+use Symfony\Component\Routing\Generator\UrlGenerator;
+use Symfony\Component\Routing\Matcher\UrlMatcher;
+use Symfony\Component\Routing\RequestContext;
+use Symfony\Component\Routing\Route;
+use Symfony\Component\Routing\RouteCollection;
+
+$route = new Route('/blog/{slug}', ['_controller' => BlogController::class]);
+$routes = new RouteCollection();
+$routes->add('blog_show', $route);
+
+$context = new RequestContext();
+
+// Routing can match routes with incoming requests
+$matcher = new UrlMatcher($routes, $context);
+$parameters = $matcher->match('/blog/lorem-ipsum');
+// $parameters = [
+//     '_controller' => 'App\Controller\BlogController',
+//     'slug' => 'lorem-ipsum',
+//     '_route' => 'blog_show'
+// ]
+
+// Routing can also generate URLs for a given route
+$generator = new UrlGenerator($routes, $context);
+$url = $generator->generate('blog_show', [
+    'slug' => 'my-blog-post',
+]);
+// $url = '/blog/my-blog-post'
+```
+
+Sponsor
+-------
+
+The Routing component for Symfony 6.4 is [backed][1] by [redirection.io][2].
+
+redirection.io logs all your website’s HTTP traffic, and lets you fix errors
+with redirect rules in seconds. Give your marketing, SEO and IT teams the
+right tool to manage your website traffic efficiently!
+
+Help Symfony by [sponsoring][3] its development!
+
+Resources
+---------
+
+ * [Documentation](https://symfony.com/doc/current/routing.html)
+ * [Contributing](https://symfony.com/doc/current/contributing/index.html)
+ * [Report issues](https://github.com/symfony/symfony/issues) and
+   [send Pull Requests](https://github.com/symfony/symfony/pulls)
+   in the [main Symfony repository](https://github.com/symfony/symfony)
+
+[1]: https://symfony.com/backers
+[2]: https://redirection.io
+[3]: https://symfony.com/sponsor