Minor doc changes

docs/strategy-callbacks.md

@@ -46,6 +46,9 @@ class AwesomeStrategy(IStrategy):
             self.cust_remote_data = requests.get('https://some_remote_source.example.com')
 
 ```
+
+During hyperopt, this runs only once at startup.
+
 ## Bot loop start
 
 A simple callback which is called once at the start of every bot throttling iteration (roughly every 5 seconds, unless configured differently).

freqtrade/strategy/hyper.py

@@ -86,7 +86,10 @@ class HyperStrategyMixin:
         return params
 
     def ft_load_hyper_params_from_file(self) -> None:
-        """ Load Parameters from parameter file"""
+        """
+        Load Parameters from parameter file
+        Should/must run before config values are loaded in strategy_resolver.
+        """
         if self._ft_params_from_file:
             # Set parameters from Hyperopt results file
             params = self._ft_params_from_file