Updates to pull-request template and assets submodule

[JoseEmilio-ARM]

Pull Request Template

Description

Fix link to wiki in CONTRIBUTING.md
In the pull-request template:

• Removed Copyright notice
• Fixed typo ('=' should be '-')
• Fixed links to other files

Updated assets SHA to point to latest master

Checklist:

• n/a My code follows the coding style
• n/a I have performed a self-review of my own code
• n/a I have commented my code, particularly in hard-to-understand areas
• n/a I have made corresponding changes to the documentation
• n/a I have tested my sample on at least one compliant Vulkan implementation
• n/a I have stated on what implementation the sample has been tested so that others can test on different implementations and platforms
• n/a My changes do not add any new compiler warnings
• n/a Vulkan validation layer output is clean on at least one compliant implementation
• n/a Any dependent changes (e.g. assets) have been merged and published in downstream modules
• n/a I have used existing framework/helper functions where possible
• I have reviewed file licenses
• n/a My changes build and run on Windows, Linux, macOS and Android. Otherwise I have documented any exceptions

[ghost]

I am not seeing check boxes, I guess that is just a bug.

What about those templates that we're mentioned, should we be using those?

[JoseEmilio-ARM]

I am not seeing check boxes, I guess that is just a bug.

What about those templates that we're mentioned, should we be using those?

I think we are already using the templates that you are referring to. In this case I replaced the checkboxes with 'n/a' since this is a small documentation change, no source code was added/modified.