Create page to document the Deprecations model

[gtfierro]

• how to lookup if something is deprecated, and what to replace it with
• how to use SHACL inference to address deprecations
• point out that the deprecation notice definition will nearly always exist in the Brick distribution when possible. There may be future incompatibilities, which we will address as needed. Any removal of deprecation information will be done with plenty of notice

[gtfierro]

Add info on versions: minor version = no breaking changes = you can add new (sub)classes, deprecate classes, and even undeprecate classes, but you cannot remove classes or change disjointness, etc.