Define 'breaking change' for Ably SDKs #46
Description
In #45 we're starting to flesh out what a 'version bump' means for an Ably SDK, including what should trigger different grades of bump (major vs minor, etc..).
There are scenarios where we may need to present a 'breaking change' where there is no change to user-facing SDK APIs. We should produce some guidance around what Ably considers a breaking SDK change in relation to less obvious edge cases (e.g. dropping support for a platform/runtime version).
As pointed out and illustrated in more detail by @owenpearson in this comment,