docs: tidy up the SECURITY.md (#271)

Signed-off-by: Shigure Kurosaki <[email protected]>

.github/SECURITY.md

@@ -2,15 +2,11 @@
 
 ## Supported Versions
 
-The [latest release](https://github.com/kurosakishigure/katharsis/releases/latest) of Katharsis, as published on GitHub under the latest release tag, is supported with security updates.
+The [latest](https://github.com/kurosakishigure/katharsis/releases/latest) version of Katharsis on GitHub supports immediate security updates.
 
 ## Reporting a Vulnerability
 
-Once the issue has been identified, we will disclose the relevant information as soon as possible.
-
-Here are the project’s key personnel and their reporting methods:
-
-- Shigure Kurosaki - [security.txt](https://hqsy.net/.well-known/security.txt)
+Please use [security.txt](https://hqsy.net/.well-known/security.txt) to report a vulnerability.
 
 You can expect a response within 48 hours if you are a human reporting a genuine issue.