clean up docs

I don't know if it's as meaningful to have verbose docs where when you
can just run the server and see the docs on the front page.

Change-Id: I9245044a95b5c0e100e14c718cdc99f560dfa3a5

doc.go

@@ -1 +1,21 @@
+/*
+Package vain implements a vanity service for use by the the go tool.
+
+
+The executable, cmd/vaind, is located in the respective subdirectory. vaind,
+a webserver for hosting go get vanity urls.
+
+The go get command searches for the following header when searching for
+packages:
+
+	<meta name="go-import" content="import-prefix vcs repo-root">
+
+this is simply a service for aggregating a collection of prefix, vcs, and
+repo-root tuples, and serving the appropriate header over http. For more
+information please refer to the documentation for the go tool found at
+https://golang.org/cmd/go/#hdr-Remote_import_paths
+
+For instructions on how to use this service, build the daemon, run it, and
+visit the root url.
+*/
 package vain