Renamed part description files to target description files.

Introduced a generic target description file class with an AVR8 derivation.
Moved AVR8 target description files

src/Targets/TargetDescription/Signal.hpp

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <string>
+#include <optional>
+
+namespace Bloom::Targets::TargetDescription
+{
+    struct Signal
+    {
+        std::string padName;
+        std::string function;
+        std::optional<int> index;
+        std::string group;
+    };
+}