Create simple PR Template for adding KIP names to README

[LindaOrtega]

Create a simple PR template that asks anyone creating a new KIP to list the KIP name in the README.

Motivation:

• Making sure that the list of KIPs is up to date.
• Ideally, we only want to ask people creating a new KIP to do this.

Related to:

• List KIPs by name in the README #47
• added list of KIPs into README.md #48 (blocked by this PR being merged)

Some potential useful resources:

• https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/creating-a-pull-request-template-for-your-repository
• https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/about-issue-and-pull-request-templates
• https://axolo.co/blog/p/part-3-github-pull-request-template
• https://github.com/kadena-community/kadena.js/tree/main/.github/ISSUE_TEMPLATE (a complex example from kadena.js)