Replace the placeholder pdf with JotForm

[rngadam]

Should be easy for visiting potential clients to self-serve the retainer agreement based on this:

https://docs.google.com/document/d/1eoEYLPZ52DlUBUkvddIcqBRvQXvjFitIjd_PBoyjrFE/edit

Visiting client should be able to fill in an HTML form, digitally sign and get a PDF that they can submit to us.

[rngadam]

let's use the jotform placeholder we created @Carms-dev

[carms-ng]

Refer to #16

[carms-ng]

Date fields added for contract start & end, which are reflected dynamically in the terms.