Need to complete the docs for the predictive intellisense feature in 2.2.0

[daxian-dbw]

Prerequisites

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Issue summary

1. Documentation content
   • 2.2-rc blog: https://devblogs.microsoft.com/powershell/psreadline-2-2-rc/
2. Sample code for the predictor plugin and related APIs.
   • Sample code is ready.
3. Fix all issues resulted from help content check by running .\build.ps1 -Configuration Release -Framework net461 -CheckHelpContent.
   • Fix mismatching key bindings for PSReadLine 2.2 MicrosoftDocs/PowerShell-Docs#8497
   • Update the HelpInfoURI to point to the latest help content #3171