Also deprecate the `window.ActivateWorkflowActionsForDashboard` and
`window.ActivateWorkflowActionsForEditView` functions as they no longer
need to be globally-accessible
- Changed all British spellings to American spellings, in the Customizing admin templates section of the docs
- Transferred all British spellings in the usage guide and advanced topics section to American spellings
- Update a series of other pages to use the spelling cutomize in the file name
Implemented all feedbacks on the usage guide and advanced topics section
