Fix wrong config strings in example file

This fixes the errors:
> module 'config' has no attribute 'keep_pinned'

and:
> module 'config' has no attribute 'keep_pinned'

example.config.py

@@ -1,7 +1,7 @@
 access_token = 'YOUR_ACCESS_TOKEN_HERE'
 base_url = 'https://ausglam.space'
 days_to_keep = 30
-save_pinned = True
-toots_to_save = []
+keep_pinned = True
+toots_to_keep = []
 hashtags_to_keep = {'introduction', 'announcement'} # comma separated Set as strings, e.g. 'introduction'
-visibility_to_keep = ['private', 'unlisted'] # options are: 'public', 'unlisted', 'private', 'direct'
+visibility_to_keep = ['private', 'unlisted'] # options are: 'public', 'unlisted', 'private', 'direct'