message: docs: update node versioning policy to be less optimistic
diff: @@ -144,9 +144,10 @@ following schedule for determining the [Node.js releases](https://nodejs.org/en/
  - At any given point in time we support exactly two adjacent even-numbered
  releases of Node.js, for example v12 and v14.
  -- Three months before a Node.js release becomes _Active LTS_ we switch support
  - to that release and the previous one. This is halfway through the _Current LTS_
  - cycle for that release and occurs at the end of July every year.
  +- Once a new Node.js release becomes _Active LTS_ we switch to support that
  + release and the previous one. The switch is not immediate but done as soon
  + as possible. You can find the Node.js version supported by each release
  + in the `engines` field in the root `package.json` of a new app.
  When we say _Supporting_ a Node.js release, that means the following:
  