feat: link methods in javadocs to source code

[samfreund]

Description

When in javadocs, clicking on a method will open the source code for that method. This is currently implemented for the WPILib javadocs, and I'm just stealing it from there.

closes #1865

Meta

Merge checklist:

• Pull Request title is short, imperative summary of proposed changes
• The description documents the what and why
• If this PR changes behavior or adds a feature, user documentation is updated
• If this PR touches photon-serde, all messages have been regenerated and hashes have not changed unexpectedly
• If this PR touches configuration, this is backwards compatible with settings back to v2024.3.1
• If this PR addresses a bug, a regression test for it is added

[mcm001]

It'd be really really cool if we could preview what the javadocs will look like. Do you know if there's a good way to just host them on read the docs as static assets?

[samfreund]

It'd be really really cool if we could preview what the javadocs will look like. Do you know if there's a good way to just host them on read the docs as static assets?

Not on RTD, but it looks like we might be able to publish a github pages preview.

Edit: It looks like we can probably modify photon-code-docs to publish a preview to github pages when it's on a PR.