Making a Will is not about wealth it is about making sure that what you want to happen to your estate does happen. It gives you the opportunity to specify such things as who will administer your estate, who will care for your children and who will receive specific items of your property.
No unfortunately it is not that simple. Making a will is a legal document. For a legal document to be valid it requires witnesses and signatures.
Signing a pdf digitally might not hold up in court and in the event of your death is anyone going to have a record of your Google docs account?
There are many websites that will create it for you (and charge). They will however post it to you for witnessing etc.
See: 'I'm making a digital will': Don't let your online assets die with you, http://www.thisismoney.co.uk/money/pensions/article-2215330/Im-making-digital-Dont-let-online-assets-die-you.html