One might carelessly misread a sentence that begins “data races
are *mostly* prevented” as suggesting that Rust fails to prevent some
data races. Clarify the intended reading.
Signed-off-by: Anders Kaseorg <andersk@mit.edu>
The section on preventing general race conditions is a bit hand wavy. Change
wording to be more concrete, and add an example of Rust preventing general
races in a very specific case.