[Maffooch]

Description

Documentation only. The PSIRT feeds page listed the Linux kernel CVE git repository as a source whose transport was "coming soon". DefectDojo Pro now fetches that source (git.kernel.org/pub/scm/linux/security/vulns.git) over the git protocol, so this change:

• narrows the "transport coming soon" note to the two sources still waiting (Ubuntu Security Notices and Exploit-DB);
• adds a short "Linux Kernel CVEs" section: its licence (the CVE Terms of Use the repository ships), what the first poll downloads (the current tree, about 70 MB, importing the published CVEs from the last two CVE years) and the 300-second poll timeout it ships with, that later polls fetch only what changed, the outbound host it needs, and how its records are dated (the records carry no publication date).

This should merge together with the matching DefectDojo Pro change, so the docs are not live before the feature ships.

Test results

Docs-only change; no code touched.

Documentation

This PR is the documentation change.