add licenses

[samfreund]

This PR adds the CC4 and BSD3 licenses for the project. It also applies the BSD3 license as a header across code files.

[github-actions]

🌐 Preview URL: https://pr-71.frcsoftware.pages.dev

[samfreund]

@Adrianamm @zachwaffle4 @roboteer5291 @Spaceman113138 @Daniel1464 @ArchdukeTim @DylanB5402 @EdanThomton

Can you all please comment with the below text to indicate your assent to this licensing? If you have any questions, feel free to ping me on discord or ask here.

I assent to licensing all of my prior contributions that consisted of website content (files that are NOT currently in the [examples](https://github.com/frcsoftware/frcsoftware.org/tree/2889ac24c65d99f9fab3858803c979e9809a3bba/examples) directory) under CC BY-NC-SA 4.0. 
I also assent to license any of my prior contributions of code (files that are currently in the [examples](https://github.com/frcsoftware/frcsoftware.org/tree/2889ac24c65d99f9fab3858803c979e9809a3bba/examples) directory), under the BSD 3-Clause license. 
I understand that all my contributions going forward will now be under these licenses.

[roboteer5291]

I assent to licensing all of my prior contributions that consisted of website content (files that are NOT currently in the [examples](https://github.com/frcsoftware/frcsoftware.org/tree/2889ac24c65d99f9fab3858803c979e9809a3bba/examples directory) under CC BY-NC-SA 4.0.
I also assent to license any of my prior contributions of code (files that are currently in the [examples](https://github.com/frcsoftware/frcsoftware.org/tree/2889ac24c65d99f9fab3858803c979e9809a3bba/examples directory), under the BSD 3-Clause license.
I understand that all my contributions going forward will now be under these licenses.

[Spaceman113138]

I assent to licensing all of my prior contributions that consisted of website content (files that are NOT currently in the [examples](https://github.com/frcsoftware/frcsoftware.org/tree/2889ac24c65d99f9fab3858803c979e9809a3bba/examples directory) under CC BY-NC-SA 4.0.
I also assent to license any of my prior contributions of code (files that are currently in the [examples](https://github.com/frcsoftware/frcsoftware.org/tree/2889ac24c65d99f9fab3858803c979e9809a3bba/examples directory), under the BSD 3-Clause license.
I understand that all my contributions going forward will now be under these licenses.

[Daniel1464]

I assent to licensing all of my prior contributions that consisted of website content (files that are NOT currently in the examples directory) under CC BY-NC-SA 4.0.
I also assent to license any of my prior contributions of code (files that are currently in the examples directory), under the BSD 3-Clause license.
I understand that all my contributions going forward will now be under these licenses.

[Adrianamm]

I assent to licensing all of my prior contributions that consisted of website content (files that are NOT currently in the examples directory) under CC BY-NC-SA 4.0.
I also assent to license any of my prior contributions of code (files that are currently in the examples directory), under the BSD 3-Clause license.
I understand that all my contributions going forward will now be under these licenses.

[zachwaffle4]

I assent to licensing all of my prior contributions that consisted of website content (files that are NOT currently in the examples directory) under CC BY-NC-SA 4.0.
I also assent to license any of my prior contributions of code (files that are currently in the examples directory), under the BSD 3-Clause license.
I understand that all my contributions going forward will now be under these licenses.