swift

624d8d67 - [Userdocs] Revise Sendable, isolation userdocs for clarity and suggestions

[Userdocs] Revise Sendable, isolation userdocs for clarity and suggestions Adds some suggestions, clarifies code examples + fixes their style a bit. Exploring using only 'isolation' instead of 'concurrency context' / 'isolation domain' and similar terms. (cherry picked from commit fb33798856085d7f75f7708ccd6bf5f886c4a57e)