[DECISION] Add RFC for top level span creation method

[Abhijeet Prasad]

ref:

• getsentry/sentry-laravel#598

• getsentry/sentry-java#1154

• getsentry/sentry-javascript#3753

Introduce a Sentry.trace method that wraps a callback with a created span.

[Neel Shah]

in ruby we just added
getsentry/sentry-ruby#1783
we can rename in a major for consistency if this becomes unified API

[Abhijeet Prasad]

Wrote out why this is need for OpenTelemetry here: getsentry/develop#720