doc: add nodejs-sec email template

This commit adds a suggestion for a template to be used as part of the
security release process. One step of this process is to create an email
to nodejs-sec group and currently would contain a copy and pasted
version of what is published on nodejs.org. This suggestion is to
instead use a link to the blog post.

Refs: nodejs#38143

doc/guides/security-release-process.md

@@ -38,6 +38,12 @@ information described.
   * Described in the pre/post announcements
 
 * [ ] Pre-release announcement [email][]: ***LINK TO EMAIL***
+  ```
+  Security updates for all active release lines, Month Year
+
+  The Node.js project will release new versions of all supported release lines on or shortly after Day of week, Month Day of Month, Year
+  For more information see: https://nodejs.org/en/blog/vulnerability/month-year-security-releases/
+  ```
   (Get access from existing manager: Ben Noordhuis, Rod Vagg, Michael Dawson)
 
 * [ ] Pre-release announcement to nodejs.org blog: ***LINK TO BLOG***
@@ -64,6 +70,12 @@ information described.
 * [ ] [Unlock CI](https://github.com/nodejs/build/blob/HEAD/doc/jenkins-guide.md#after-the-release)
 
 * [ ] Post-release announcement in reply [email][]: ***LINK TO EMAIL***
+  ```
+  Security updates for all active release lines, Month Year
+
+  The Node.js project has now released new versions of all supported release lines.
+  For more information see: https://nodejs.org/en/blog/vulnerability/month-year-security-releases/
+  ```
 
 * [ ] Post-release announcement to Nodejs.org blog: ***LINK TO BLOG POST***
   * (Re-PR the pre-approved branch from nodejs-private/nodejs.org-private to