align hoverlabels left and constant-size legend items in builtin themes

Author: nicolaskruchten

Diff for: templategen/utils/__init__.py

@@ -72,6 +72,12 @@ def initialize_template(annotation_defaults,
     # hovermode
     template.layout.hovermode = 'closest'
 
+    # right-align hoverlabels
+    template.layout.hoverlabel.align = 'left'
+
+    # fix size of legend items
+    template.layout.legend.itemsizing = 'constant'
+
     # Set background colors
     template.layout.paper_bgcolor = paper_clr
     template.layout.plot_bgcolor = panel_background_clr