fix: copy more than just rst files

Now that we use literalinclude, source files include more than just rst
files. I'd say anything with an extension goes.

Files that are not rst files should be copied verbatim.

This addresses an issue with guides not finding files referenced in
literalinclude directives, because they were never copied.

lib/Docs/RST/RSTCopier.php

@@ -12,6 +12,7 @@
 use function file_exists;
 use function is_string;
 use function preg_replace;
+use function str_ends_with;
 use function str_replace;
 
 /** @final */
@@ -55,6 +56,11 @@ public function copyRst(Project $project, ProjectVersion $version): void
                     continue;
                 }
 
+                if (! str_ends_with($file, '.rst')) {
+                    $this->filesystem->copy($file, $outputPath . str_replace($language->getPath(), '', $file));
+                    continue;
+                }
+
                 $this->copyFile(
                     $project,
                     $version,

lib/Docs/RST/RSTFileRepository.php

@@ -58,7 +58,7 @@ public function getSourceFiles(string $path): array
 
         $finder = $this->getFilesFinder($path);
 
-        $finder->name('*.rst');
+        $finder->name('*.*');
         $finder->notName('toc.rst');
 
         return $this->finderToArray($finder);