Build: Publish machine-readable file list and SRI data to resources/

Let "wordpress-deploy" upload this to the site, which the gw-resources
plugin exposes via addresses like <https://releases.jquery.com/resources/foo>.

See <https://github.com/jquery/api.jquery.com/> for an example of this.

Local test plan:

```
nobody$ npm ci
nobody$ cp config-sample.json config.json

nobody$ ./node_modules/.bin/grunt sri
nobody$ less resources/sri-directives.json
  {"@cdn/color/2.2.0/jquery.color.js":{"hashes":{"sha256":"gvMJWDH...

nobody$ ./node_modules/.bin/grunt build-index build-resources
nobody$ less dist/wordpress/resources/sri-directives.json
  {"@cdn/color/2.2.0/jquery.color.js":{"hashes":{"sha256":"gvMJWDH...
nobody$ less dist/wordpress/resources/cdn.json
  { "jquery": [ [ "3", { "latestStable": {
  "filename": "jquery-3.6.0.js", ...
```

Closes #40.

Author: Krinkle

.gitignore

@@ -1,4 +1,5 @@
 /node_modules/
 /dist/
+/resources/sri-directives.json
 /git/
 /config.js*

Gruntfile.js

@@ -17,7 +17,7 @@ grunt.initConfig( {
 			],
 			options: {
 				algorithms: ["sha256"],
-				dest: "dist/resources/sri-directives.json"
+				dest: "resources/sri-directives.json"
 			}
 		}
 	},
@@ -28,7 +28,14 @@ grunt.initConfig( {
 		var config = require( "./config" );
 		config.dir = "dist/wordpress";
 		return config;
-	})()
+	})(),
+
+	// This copies /resources/* to /dist/wordpress/resources/*,
+	// This is flattened (subpaths not preserved) to just base filenames,
+	// and then uploaded by "wordpress-deploy" to the web server.
+	"build-resources": {
+		all: "resources/**"
+	}
 } );
 
 grunt.registerTask( "build-index", function() {
@@ -310,7 +317,7 @@ grunt.registerTask( "build-index", function() {
 		};
 	}
 
-	var sriHashes = require( "./dist/resources/sri-directives.json" );
+	var sriHashes = require( "./resources/sri-directives.json" );
 
 	function cdnSriLink( file, label ) {
 		var sri = "sha256-" + sriHashes[ `@cdn/${ file }` ].hashes.sha256,
@@ -426,6 +433,9 @@ grunt.registerTask( "build-index", function() {
 
 	grunt.file.write( "dist/wordpress/posts/page/pep.html",
 		Handlebars.compile( grunt.file.read( "templates/pep.hbs" ) )( data ) );
+
+	grunt.file.write( "dist/wordpress/resources/cdn.json",
+			JSON.stringify( data, null, 2 ) );
 } );
 
 grunt.registerTask( "reload-listings", function() {
@@ -455,16 +465,12 @@ grunt.registerTask( "reload-listings", function() {
 	} );
 } );
 
-grunt.registerTask( "ensure-dist-resources", function() {
-	grunt.file.mkdir( "dist/resources" );
-} );
-
 grunt.registerTask( "sri-generate", ["ensure-dist-resources", "sri:generate"] );
 
 // The "grunt deploy" command is automatically invoked on git-commit by the server that
 // will deploy the WordPress site.
 // Task tree: "deploy" > "wordpress-deploy" > "build-wordpress" > "build".
-grunt.registerTask( "build", ["sri-generate", "build-index"] );
+grunt.registerTask( "build", ["sri-generate", "build-index", "build-resources"] );
 grunt.registerTask( "deploy", ["wordpress-deploy", "reload-listings"] );
 
 };