Reorder summary in order of importance (#12433)

* feat: breaking changes should be the first heading

Signed-off-by: Manan Gupta <manan@planetscale.com>

* feat: reorder the breaking changes in order of user impact

Signed-off-by: Manan Gupta <manan@planetscale.com>

* feat: VTOrc becoming mandatory is important

Signed-off-by: Manan Gupta <manan@planetscale.com>

* Reorganize the flag deletions and deprecation announcements

Signed-off-by: Florent Poinsard <florent.poinsard@outlook.fr>

* Fix various typo and add vtorc links

Signed-off-by: Florent Poinsard <florent.poinsard@outlook.fr>

* Upgrading to this release with vitess-operator

Signed-off-by: Florent Poinsard <florent.poinsard@outlook.fr>

* Fix various typo

Signed-off-by: Florent Poinsard <florent.poinsard@outlook.fr>

* Link to PRs in major changes

Signed-off-by: Florent Poinsard <florent.poinsard@outlook.fr>

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Signed-off-by: Manan Gupta <manan@planetscale.com>
Signed-off-by: Florent Poinsard <florent.poinsard@outlook.fr>
Co-authored-by: Florent Poinsard <florent.poinsard@outlook.fr>