Skill types

[Skivling]

I have been thinking about the approach I will take when organising skills to be taught to the learner in my app and I think it would be great to have an identifier for Skills.

Skills will remain being loosely defined and able to include any number of Words, Phrases or Characters (#1143). That flexibility is important to be able to adapt to any teacher's needs.

However:

• It would be nice to have separated vocabulary lists disconnected from the main skills.
• It would be nice to separate Character skills (when those are implemented - which I may do sometime)
• I would like to have a separate section in my app for teaching extended vocabulary lists.

I propose:

• Skills can have an optional parameter which suggests what kind of skill they are.
  • mixed is the default and can includes any amount of Words, Phrases or Characters.
  • vocabulary (or vocab?) specifically includes a list of vocabulary Words and no Phrases or Characters. These can be created according to specific themes, such as 'Common Jobs'
  • character specifically if the course includes a whole new script and it is useful to separate them from mixed skills.
  • phrase - I can't see a use case for this, there isn't much distinction between a phrase type and a mixed type that only has Phrases; but it would be good to support it in case it is useful sometime.
  • conversation for [Feature Request] Conversation challenge #3388 when that is implemented.

Examples

Not everyone wants to learn the names of specific things, but it's good to be able to have vocabulary lists not required to learn, but available.

Skill:
  Id: c6e16576-76cb-4507-a86c-db416e43fd3c
  Name: Fruit and Vegetables
  Type: vocabulary
  Thumbnails:
  ...

For someone learning a foreign alphabet such as Ukranian/Russian, these skills could be separated from the main skills so the learner can do them at their own pace.

Skill:
  Id: de2dcfac-f2ac-413f-b6ef-3315a456d3d7
  Name: А, Б, В, Г, а, б, в, г 
  Type: character
  Thumbnails:
  ...