Add CHANGELOG fragments for new CLI

[hasbro17]

Description of the change:
Add CHANGELOG fragments to document the changes for:

• removal of --type=go from operator-sdk new cmd.
• deprecation of the old CLI
• addition of the new CLI

Motivation for the change:
Follow up to #3190

[hasbro17]

Most likely waiting on #3255 to fix the sanity check for the CLI reference on master.

[hasbro17]

CI failure is for the --project-version args getting a different order every time because Go's iteration order for map keys are not the same every time.

The iteration order over maps is not specified and is not guaranteed to be the same from one iteration to the next.

diff --git a/website/content/en/docs/new-cli/operator-sdk_init.md b/website/content/en/docs/new-cli/operator-sdk_init.md
index aa850bc..b1573be 100644
--- a/website/content/en/docs/new-cli/operator-sdk_init.md
+++ b/website/content/en/docs/new-cli/operator-sdk_init.md
@@ -43,7 +43,7 @@ operator-sdk init [flags]
       --license string           license to use to boilerplate, may be one of 'apache2', 'none' (default "apache2")
       --owner string             owner to add to the copyright
       --plugins strings          Name and optionally version of the plugin to initialize the project with. Available plugins: ("go.kubebuilder.io/v2", "go.kubebuilder.io/v2")
-      --project-version string   project version, possible values: ("2", "3-alpha") (default "3-alpha")
+      --project-version string   project version, possible values: ("3-alpha", "2") (default "3-alpha")

I can restart the CI enough times to get this in though until kubernetes-sigs/kubebuilder#1564 fixes it.

[camilamacedo86]

/lgtm
/approve

[openshift-ci-robot]

New changes are detected. LGTM label has been removed.

[hasbro17]

Merging this.
@joelanford We can do a follow up if you think we need to rephrase anything.