Improve Get-RandomHtml

[afscrome]

Currently Get-RandomHtml only creates empty paragraphs. Add support for generating richer html content. (e.g. embeded images, bold, youtube embeds etc.)

https://github.com/afscrome/SampleDataGenerator/blob/17cebf71f6408d54d543cebfdfbff973324d7aad/CommunitySample/data.ps1#L3