Usability: More helpful errors on invalid sentences yaml

[flubshi]

Hi @synesthesiam ,
I noticed about rhasspy-speech in the video of the new home assistant voice pe. I prefer a cloudless voice assistant and so far I experimented with whisper and vosk. While whisper was too slow, vosk was very fast. But defining all sentences/intents for vosk was time consuming. I dreamed about auto generating vosks the sentences from home assistant's intents.

Today I experimented with rhasspy-speech and my first impression: it is absolutely awesome! rhasspy-speech combines good results with fast responses. Great work! Thank you so much - it is now my default STT.

In the beginning, I started copying my vosk sentences yaml to rhasspy-speech. Since it is a slightly different structure, I received a not very helpful error. It is already fixed for me, but I would suggest to make error messages more helpful for other users:

How to reproduce:

1. Edit sentences and use an invalid structure, e.g.

sentences:
  - "Play radio {channels}"
lists:
  channels:
    - channel1
    - channel2

or

sentences:
  - "Set brightness {brightness}"
lists:
  brightness:
    range:
      from: 1

2. Press "View Intents". A python errors appears:

AttributeError: 'list' object has no attribute 'get'

or

KeyError: 'to'

Suggestion:

From an end user perspective, a more verbose error message instead of a python error would be helpful. E.g. Invalid sentence yaml structure. The key ''to' is missing in range for brightness