Added derivation of TDF base class, for AVR8 targets.

Includes initialisation and validation code.

build/scripts/TargetDescriptionFiles/MemorySegment.php

@@ -0,0 +1,11 @@
+<?php
+namespace Bloom\BuildScripts\TargetDescriptionFiles;
+
+class MemorySegment
+{
+    public ?string $name = null;
+    public ?string $type = null;
+    public ?int $startAddress = null;
+    public ?int $size = null;
+    public ?int $pageSize = null;
+}