Define Pull Request templates

[amias-channer]

• drHEADer version: any
• Python version: any
• Operating System: any

Description

To help normalise pull requests and allow people do discover while doing
we can add a template to the repository that will define the template for new pull requests
this can also include basic requirements.

A starter set could be :

• a branch to merge from
• an issue number that describes the work
• list of tests added
• list of tests changed

This functionality to do this in github is documented here
https://help.github.com/en/github/building-a-strong-community/creating-a-pull-request-template-for-your-repository

Deliverables

create template in .github/.github/pull_request_template.md

[amias-channer]

this was , ironically violating of the policies it espouses , committed directly to master.

the dastardly behaviour was justified because if you make a branch and PR it you will get the old file in your PR.