Update docs with changes from implementing Action IDs

[PankajBhojwani]

Updates the docs page for Actions with the following changes:

• The actions examples now no longer contain keybindings
• The removed keybindings have now been moved to their own section where they refer to said actions by ID
• The list of all the available commands/actions now shows both the default ID for the in-built actions as well as their default keybindings

[learn-build-service-prod[bot]]

Learn Build status updates of commit 95f6efb:

:white_check_mark: Validation status: passed

File	Status	Preview URL	Details
TerminalDocs/customize-settings/actions.md	:white_check_mark:Succeeded	View

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[mattwojo]

@zadjii-msft / @nguyen-dows - Could you take a look?