Update_v1_0_0.md

🆙 Update to v1.0.0

If you are updating to v1.0 from a previous version, in general everything should be fine.

But, in some niche and specific cases, you may have to look out for some minor details or deprecations.

The 2 minor (but still technically breaking) changes are:

• slightly changed the nullability annotations with generics for the return values in the GetOrSet<T> and GetOrSetAsync<T>
• the FusionCacheEntryOptions.Size option went from being long to long?

Historically there have been only 2 versions that needed some attention, so please read the update notes if you are updating from a previous version:

• to update from a version before v0.20.0 (update notes)
• to update from a version before v0.24.0 (update notes)

Apart from these everything should be quite smooth.

In case something has been deprecated with time, there will be some warnings at compile time thanks to the usage of the [Obsolete] attribute along with useful instructions to follow, what to change, etc.

That's all, happy updating!