add missing base plugin defs and fix docs

plugins/plugins.py

@@ -18,6 +18,10 @@ class BasePlugin:
         pass
     def on_step_end(self, **kwargs):
         pass
+    def on_model_load(self, **kwargs):
+        pass
+    def on_model_save(self, **kwargs):
+        pass
     def on_will_step_optimizer(self, **kwargs):
         pass
     def transform_caption(self, caption:str) -> str:

plugins/textual_inversion.py

@@ -29,10 +29,11 @@ In optimizer.json, the following "text_encoder_freezing" section is *required*:
         "freeze_final_layer_norm": true,
         "freeze_position_embeddings": true
     }
-In addition, you'll need a very high LR on the TE - maybe even as high as 1e-3. I recommend using the LR finder method.
+In addition, you'll need a very high LR on the TE - maybe even as high as 5e-2. I recommend using the LR finder method.
 
 """
 
+
 class TextualInversionPlugin(BasePlugin):
 
     def __init__(self):