Readme modified to include app.module changes

[alfmoh]

Add the new import to app.module which differs from 'angular-2-data-table-demo'

[SoundharNatarajan]

Uncaught Error: Unexpected value 'DataTableModule' imported by the module 'AppModule'. Please add a @NgModule annotation.
at syntaxError (compiler.js:485)
at eval (compiler.js:15204)
at Array.forEach ()
at CompileMetadataResolver.getNgModuleMetadata (compiler.js:15187)
at JitCompiler._loadModules (compiler.js:34226)
at JitCompiler._compileModuleAndComponents (compiler.js:34187)
at JitCompiler.compileModuleAsync (compiler.js:34081)
at CompilerImpl.compileModuleAsync (platform-browser-dynamic.js:230)
at PlatformRef.bootstrapModule (core.js:5568)
at eval (webpack-internal:///../../../../../src/main.ts:13)

I am getting this error