Add a comment about cache-control headers in the patch docs.
Add a comment about cache-control headers in the patch docs.

Cache-control headers can result in updates not being found.
This adds a note to let users know this.

Change-Id: I902aefe67107d8d0f749b53927fc91e73e056a03

moham3d/tabris-js,eclipsesource/tabris-js,mkostikov/tabris-js,pimaxdev/tabris,pimaxdev/tabris,moham3d/tabris-js,mkostikov/tabris-js,eclipsesource/tabris-js,eclipsesource/tabris-js