Define and publicise our new responsible disclosure process 🐛

[JamieSlome]

As discussed in our community meeting yesterday (19th May '25), we agreed that our responsible disclosure process needs a lick of paint 🖌

Shopping List 🛒

• Verify whether we can use GitHub's responsible disclosure feature
• Enable GitHub's responsible disclosure feature
• Update the SECURITY.md to point reporters to the GitHub feature
• Add "How to report a vulnerability" in the README.md
• Update the documentation site to reflect the new responsible disclosure process

@TheJuanAndOnly99 - can you assign admin rights to me so I can setup some of the following and pass on to @sam-holmes2 for final implementation?

(cc) @tabathad

[JamieSlome]

@sam-holmes2 - enabled 👍 On to you! 🚀