[geometry-1][editorial] Split separate Privacy and Security sections, which is now required.

Author: svgeesus

geometry/Overview.bs

@@ -1730,8 +1730,9 @@ The <a>serialization steps</a> for {{DOMMatrixReadOnly}} and {{DOMMatrix}}, give
         17. Set |value|'s <a for=matrix>is 2D</a> to <code>false</code>.
 
 
-Privacy and Security Considerations {#priv-sec}
-===============================================
+
+Security Considerations {#security}
+====================================
 
 The {{DOMMatrix}} and {{DOMMatrixReadOnly}} interfaces have entry-points to parsing a string with
 CSS syntax. Therefore the <a href="https://drafts.csswg.org/css-syntax/#priv-sec">privacy and
@@ -1745,6 +1746,9 @@ There are no other known security or privacy impacts of the interfaces defined i
 specification. However, other specifications that have APIs that use the interfaces defined in this
 specification could potentially introduce security or privacy issues.
 
+Privacy Considerations {#privacy}
+=================================
+
 <div class=example>
 For example, the {{Element/getBoundingClientRect()}} API defined in CSSOM View returns a
 {{DOMRect}} that could be used to measure the size of an inline element containing some text of a