Update source/handbook/benefits/index.html.md

Why is this change being made?

Added Helpline numbers of Central team and teams from States & Union Territories for coronavirus related query and help.

cc: @gl-compensation

Does this MR meet the acceptance criteria?

Assign to DRI

• Did you assign this change to the correct DRI of the page or information you are changing?

Conformity

• Added description to this MR explaining the reasons for the proposed change, per say-why-not-just-what