Separate scripts `npm test` and `npm run build`, remove `npm run doc` from `test`

- npm doc: unchanged, but no longer called by 'test'
  * it is run on its own by 'mwext-node10-rundoc-docker' CI job.
  * successful build of the documentation is necessary for JenkinsBot to accept the patch
- npm test: runs only 'lint' as of now, future possibility: qunit tests too
  * run by CI job 'mwgate-node10-docker'
- npm build: runs 'test' and 'doc'
  * NOT run by CI jobs

Bug: T247004
Change-Id: I3e6e1ebb220ceb1a1591cb7087bbd071b1bacf8f

package.json

@@ -1,7 +1,8 @@
 {
 	"private": true,
 	"scripts": {
-		"test": "npm -s run lint && npm run doc",
+		"build": "npm -s test && npm -s run doc",
+		"test": "npm -s run lint",
 		"lint": "npm -s run lint:js && npm -s run lint:styles && npm -s run lint:i18n",
 		"lint:fix": "npm -s run lint:js -- --fix && npm -s run lint:styles -- --fix",
 		"lint:js": "eslint --cache --max-warnings 0 .",