Update Child docs to not have a note section

In #29370 it's noted that for "the Note shouldn't be one, and should come before
the examples." This commit changes the positioning of the section and removes
wording that said take note in order for it to flow better with the surrounding
text and it's new position.

Author: mgattozzi

src/libstd/process.rs

@@ -73,6 +73,15 @@ use sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
 /// spawning process and can itself be constructed using a builder-style
 /// interface.
 ///
+/// There is no implementation of [`Drop`] for child processes,
+/// so if you do not ensure the `Child` has exited then it will continue to
+/// run, even after the `Child` handle to the child process has gone out of
+/// scope.
+///
+/// Calling [`wait`][`wait`] (or other functions that wrap around it) will make
+/// the parent process wait until the child has actually exited before
+/// continuing.
+///
 /// # Examples
 ///
 /// ```should_panic
@@ -89,17 +98,6 @@ use sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
 /// assert!(ecode.success());
 /// ```
 ///
-/// # Note
-///
-/// Take note that there is no implementation of [`Drop`] for child processes,
-/// so if you do not ensure the `Child` has exited then it will continue to
-/// run, even after the `Child` handle to the child process has gone out of
-/// scope.
-///
-/// Calling [`wait`][`wait`] (or other functions that wrap around it) will make
-/// the parent process wait until the child has actually exited before
-/// continuing.
-///
 /// [`Command`]: struct.Command.html
 /// [`Drop`]: ../../core/ops/trait.Drop.html
 /// [`wait`]: #method.wait