Add doc about local catalog caching during publishing#233

HereThereBeDragons wants to merge 1 commit intocvmfs:latestcvmfs/doc-cvmfs:latestfrom

HereThereBeDragons:cvmfs_server_cache_catalogHereThereBeDragons/doc-cvmfs:cvmfs_server_cache_catalogCopy head branch name to clipboard