Switch from [contenthash] back to [fullhash] (prev [hash]) in Dev config

contenthash is not recommended in dev mode, and hash, the value we
previously used, has been renamed fullhash for clarity.

Author: kadamwhite

src/presets.js

@@ -122,9 +122,9 @@ const development = ( config = {} ) => {
 			// Add /* filename */ comments to generated require()s in the output.
 			pathinfo: true,
 			// Provide a default output name.
-			filename: '[name].[contenthash].js',
+			filename: '[name].[fullhash].js',
 			// Provide chunk filename. Requires content hash for cache busting.
-			chunkFilename: '[name].[contenthash].chunk.js',
+			chunkFilename: '[name].[fullhash].chunk.js',
 			// `publicPath` will be inferred as a localhost URL based on output.path
 			// when a devServer.port value is available.
 		},

src/presets.test.js

@@ -95,8 +95,8 @@ describe( 'presets', () => {
 			expect( config.entry ).toEqual( 'some-file.js' );
 			expect( config.output ).toEqual( {
 				pathinfo: true,
-				filename: '[name].[contenthash].js',
-				chunkFilename: '[name].[contenthash].chunk.js',
+				filename: '[name].[fullhash].js',
+				chunkFilename: '[name].[fullhash].chunk.js',
 				path: 'build/',
 			} );
 		} );