Update Plugin Inheritance in Docs

[jmcgill298]

Docs suggest to use nautobot.core.models.BaseModel, but then examples do not follow this practice

[glennmatthews]

Thank you for the PR! We should actually discuss this a bit, I think - while using BaseModel is definitely acceptable, in many cases plugins may actually be better off to use PrimaryModel or OrganizationalModel to get the extra features (change logging, custom fields, relationships) that those models provide. Maybe we stick with BaseModel for this document for the moment, and plan to create a more in-depth development guide in the future, perhaps as part of #13, #14, and/or #15?

[jmcgill298]

It seems that github is not allowing you to view markdown files as code files (non-rendered view), but these changes were made to make the examples consistent with the surrounding documentation. Line 191 says:

It is highly recommended to have plugin models inherit from at least `nautobot.core.models.BaseModel` which provides base functionality and convenience methods common to all models.

These 2 examples do not follow that recommendation currently.

I have no thoughts as far as what should be demonstrated here, only that it is consistent with what the document prescribes.

As for providing additional docs that provide deeper understanding of the options, I am definitely a fan of the idea.