Sync windows free text

[speedfl]

Summary

When navigating in sync windows it is complex to understand why they are here. Are they still applicable... It is even more complicated when they have been created manually

Motivation

Adding a sync windows free text zone could help referencing an incident number for example or JIRA issue.

Proposal

Add a non mandatory free text field such as description

apiVersion: argoproj.io/v1alpha1
kind: AppProject
metadata:
  name: default
spec:
  syncWindows:
  - kind: allow
    schedule: '10 1 * * *'
    duration: 1h
    applications:
    - '*-prod'
    manualSync: true
    description: |
      INC123456789, contact [email protected]

Additional

To consider as well here: #11755