Update SECURITY.md

Point to "report a vulnerability" tab instead of email.

SECURITY.md

@@ -12,10 +12,12 @@
 Fiona includes C extension modules that link [GDAL](https://gdal.org/), which in turn links a number of other libraries such as libgeos, libproj, and libcurl.
 The exact list depends on the features included when GDAL is built and varies across distributions.
 
-The Fiona project publishes binary wheels to the Python Package Index for 4 different platforms. The wheels contain 27-35 libraries.
+The Fiona team publishes binary wheels to the Python Package Index for 4 different platforms. The wheels contain 27-35 libraries.
 The exact list depends on the platform and the versions of package managers and tooling used for each platform. Details can be found at https://github.com/sgillies/fiona-wheels.
 
-To report a vulnerability in fiona or in one of the libraries that is included in a binary wheel on PyPI, please email [email protected].
-In the case of a vulnerability in fiona code, please provide the kind of details we ask for in a GitHub issue.
+To report a vulnerability in fiona or in one of the libraries that is included in a binary wheel on PyPI, please use the GitHub Security Advisory "Report a Vulnerability" tab.
 In the case of a vulnerability in a dependency, please provide a link to a published CVE or other description of the issue.
-Users will be notified at https://github.com/Toblerity/Fiona/discussions.
+
+The Fiona team will send a response indicating the next steps in handling your report. After the initial reply to your report, the security team will keep you informed of the
+progress towards a fix and full announcement at https://github.com/Toblerity/Fiona/discussions, and may ask for additional information or guidance.
+