Update SECURITY.md to match template

SECURITY.md

@@ -4,19 +4,20 @@
 
 If you discover a security vulnerability, please follow these steps:
 
-1. **Do not** create an issue on this repository, **Do not** disclose the vulnerability publicly
-1. In the top navigation of this repository, click the **Security** tab.
-1. In the top right, click the **Report a vulnerability** button.
-1. Fill out the provided form. It will request information like:
+1. **Do not** create a public issue on this repository.
+2. In the top navigation of this repository, click the **Security** tab.
+3. In the top right, click the **Report a vulnerability** button.
+4. Fill out the provided form with:
    - A description of the vulnerability
    - Steps to reproduce the issue
-   - Potential impact on student data or website functionality
+   - Potential impact
    - Suggested fix (if you have one)
 
 ## Response Timeline
-TBD/ASAP
+
+We will acknowledge your report within 48 hours and provide an estimated timeline for a fix.
 
 ## Thank You
 
 Your help is greatly appreciated!
-Responsible disclosure of security vulnerabilities helps protect our entire community
+Responsible disclosure of security vulnerabilities helps protect our entire community.