Added support for training lora, dreambooth, and fine tuning. Still need testing and docs

extensions_built_in/sd_trainer/__init__.py

@@ -0,0 +1,30 @@
+# This is an example extension for custom training. It is great for experimenting with new ideas.
+from toolkit.extension import Extension
+
+
+# This is for generic training (LoRA, Dreambooth, FineTuning)
+class SDTrainerExtension(Extension):
+    # uid must be unique, it is how the extension is identified
+    uid = "sd_trainer"
+
+    # name is the name of the extension for printing
+    name = "SD Trainer"
+
+    # This is where your process class is loaded
+    # keep your imports in here so they don't slow down the rest of the program
+    @classmethod
+    def get_process(cls):
+        # import your process class here so it is only loaded when needed and return it
+        from .SDTrainer import SDTrainer
+        return SDTrainer
+
+
+# for backwards compatability
+class TextualInversionTrainer(SDTrainerExtension):
+    uid = "textual_inversion_trainer"
+
+
+AI_TOOLKIT_EXTENSIONS = [
+    # you can put a list of extensions here
+    SDTrainerExtension, TextualInversionTrainer
+]