Add base files for bindings

Add base files for C++ and D that will interface with the existing C integration.

.gitignore

@@ -11,6 +11,9 @@
 !build.sh
 !CHANGELOG
 !configure.ac
+!dub.sdl
+!dub.selections.json
+!extension_api.json
 !LICENSE
 !Makefile.am
 !README
@@ -39,6 +42,7 @@
 /engine/bin/*
 
 !/engine/bin/librtr.gdextension
+!/engine/bin/libsb.gdextension
 
 # /engine/img
 !/engine/img/
@@ -56,6 +60,26 @@
 !/src/main.gdextension
 !/src/main.h
 
+# /src/init
+!/src/init
+/src/init/*
+
+!/src/init/bind.d
+
+# /src/init/cpp
+!/src/init/cpp
+/src/init/cpp/*
+
+!/src/init/cpp/bind.cpp
+
+# /src/init/d
+!/src/init/d
+/src/init/d/*
+
+/src/init/d/bind.d
+
+!/src/init/d
+
 # /res
 !/res/
 /res/*