(DOCSP-26870) Updates support lifecycle intro paragraph (#1157)

* (DOCSP-26870) Updates support lifecycle intro paragraph

* Includes change from tech review

* Includes change from copy review

Author: sarahsimpers

source/reference/support-lifecycle.txt

@@ -12,11 +12,12 @@ Support Lifecycle
    :depth: 1
    :class: singlecol
 
-The support lifecycle of the |k8s-op| is governed by the `MongoDB
-Support Policy <https://www.mongodb.com/support-policy>`__, where the
-|k8s-op-short| is considered an "extension to |onprem|". The following
-dates are derived from this policy and are published here for guidance
-only. These dates might be subject to change.
+The support lifecycle of the |k8s-op| is, by default, 9 months x 31
+days each month (279 days total) from the release date of a major
+version. Versioning of the |k8s-op-short| does not follow semantic
+versioning convention, and a major version of the |k8s-op-short| is 
+X.X. (for example, 1.17 or 1.18). The following dates might be subject
+to change.
 
 .. list-table::
    :header-rows: 1