Task 981415: FAQ for sensitivity labels for Excel#1611

SivakumarRamya wants to merge 3 commits intohotfix/hotfix-v31.2.2syncfusion-content/document-processing-docs:hotfix/hotfix-v31.2.2from

981415-Sensitivity--Labelssyncfusion-content/document-processing-docs:981415-Sensitivity--LabelsCopy head branch name to clipboard