{get 'name'} asks the web server for another page of this application and
puts what comes back in place of the tag. Unlike {page}, which builds
the page inside the current request, this is a real second HTTP request: the page runs in a
fresh process, with its own variables, and sees nothing of the page that asked for it.
The page is fetched with &padInclude, so it renders bare - without its
_inits.pad/_exits.pad wrappers. Every variable assigned on the tag,
{get 'badge', $colour = 'red'}, goes along on the query string, where the other
page finds it as a request value. The answer is inserted as a value: its braces are text and
are not parsed again.
The fetch goes to the server's own address, never to the host a request names. Under the
strict check a page that does not exist is an error before any request is made. Because it
costs a round trip, {get} is for the case where the isolation of a separate
request is the point; {page} is faster and shares the request. Remote
addresses are fetched with {curl}; a stored content block is read
with {content:name}.