Change PDF link on the index page to point to the main web page

[goneall]

Questionnaire PDF documents are being moved from the Questionnaire generated PDFs to a more professional PDF on the main openchain project website.

Once the new URL is live, the link should be updated.

[goneall]

@shanecoughlan Please update the issue once the URL is live.

[goneall]

The preferred link is https://github.com/OpenChain-Project/Reference-Material/raw/master/Checklists/Official/Self-Certification-Questionnaire/2.1/en/openchain-self-certification-questionnaire-2.1-iso-5230-V1.pdf

However, this causes a popup when clicked.

Rather than linking to the new document, we can update the formatting of the generated document to match. Attached is a mock-up of the proposed format from a prototype generated PDF.

This approach has the advantage of being localized and the downloaded PDF will match the language preference of the user.
questionnaire-proposed-format.pdf