Rename javascript package to @zuul-ci/dashboard

The python service is "zuul-web", but the javascript portion is
currently also being built as "zuul-web". While the javascript code is
intended to be served by zuul-web, not having its own name has made it
awkward to be clear about which codebase is being discussed.

npm has also added namespacing to published modules, which allows
grouping modules and is indicated by the @ prefix.

Update the config to call the javascript code '@zuul-ci/dashboard'. This
will allow us to add an npm publication job, although we need to set up
some accounts for that first.

Change-Id: I6e31ae23f74f887448f0a48147d91c156025e925

doc/source/developer/javascript.rst

@@ -1,8 +1,8 @@
 Zuul Web Javascript
 ===================
 
-zuul-web has an html, css and javascript component that is managed
-using Javascript toolchains. It is intended to be served by zuul-web
+zuul-web has an html, css and javascript component, `zuul-dashboard`, that
+is managed using Javascript toolchains. It is intended to be served by zuul-web
 directly from zuul/web/static in the simple case, or to be published to
 an alternate static web location, such as an Apache server.
 

package.json

@@ -1,7 +1,7 @@
 {
-  "name": "zuul-web",
+  "name": "@zuul-ci/dashboard",
   "version": "1.0.0",
-  "description": "Web Client for Zuul",
+  "description": "Web Dashboard for Zuul",
   "main": "index.js",
   "repository": "https://git.openstack.org/openstack-infra/zuul",
   "author": "OpenStack Infra",