Add help short description and long description to code first import process

[nkramaric]

Is your feature request related to a problem? Please describe.

We would like to be able to add help text - short description and long description for a template field via the code-first import process. We often like to include image aspect ratios or additional context in these fields that helps content authors.

Describe the solution you'd like

Add helpTextShortDescription and helpTextLongDescription fields to the FieldDefinition object for the code-first JSS template and component models.

Describe alternatives you've considered

We have considered switching to Sitecore-first. However, this does not feel like a good enough reason alone to completely switch our development workflow.

Additional information

I am happy to try and implement this if someone can point to the packages/files that need to be updated.