Add svgRule exclude in the docs

[droyson]

It would be good to add the following line in the Enabling the emoji plugin docs
svgRule.exclude.add(path.join(__dirname, 'node_modules', '@wwalc'));

Will save some time for developers like myself in figuring this out.

[enzolry]

It would be good to add the following line in the Enabling the emoji plugin docs
svgRule.exclude.add(path.join(__dirname, 'node_modules', '@wwalc'));

Will save some time for developers like myself in figuring this out.

I agree, you saved me some time !