Manipulates packages cache
+npm cache add <tarball file>
+npm cache add <folder>
+npm cache add <tarball url>
+npm cache add <name>@<version>
+
+npm cache ls [<path>]
+
+npm cache clean [<path>]
+Used to add, list, or clear the npm cache folder.
+add: +Add the specified package to the local cache. This command is primarily +intended to be used internally by npm, but it can provide a way to +add data to the local installation cache explicitly.
+ls:
+Show the data in the cache. Argument is a path to show in the cache
+folder. Works a bit like the find program, but limited by the
+depth config.
clean: +Delete data out of the cache folder. If an argument is provided, then +it specifies a subpath to delete. If no argument is provided, then +the entire cache is cleared.
+npm stores cache data in the directory specified in npm config get cache.
+For each package that is added to the cache, three pieces of information are
+stored in {cache}/{name}/{version}:
Additionally, whenever a registry request is made, a .cache.json file
+is placed at the corresponding URI, to store the ETag and the requested
+data. This is stored in {cache}/{hostname}/{path}/.cache.json.
Commands that make non-essential registry requests (such as search and
+view, or the completion scripts) generally specify a minimum timeout.
+If the .cache.json file is younger than the specified timeout, then
+they do not make an HTTP request to the registry.
Default: ~/.npm on Posix, or %AppData%/npm-cache on Windows.
The root cache folder.
+