Update security policy guidelines

This is the latest version from our template repo.

Author: mhucka

.github/SECURITY.md

@@ -1,19 +1,25 @@
 # Reporting security issues
 
-The ReCirq developers and community take security bugs in ReCirq seriously.
-We appreciate your efforts to responsibly disclose your findings, and will make
-every effort to acknowledge your contributions.
+This project's developers and community are committed to addressing security
+bugs promptly and effectively. We appreciate your efforts to disclose your
+findings responsibly, and will make every effort to acknowledge your
+contributions.
 
 Please **do not** use GitHub issues to report security vulnerabilities; GitHub
 issues are public, and doing so could allow someone to exploit the information
-before the problem can be addressed. Instead, please use the GitHub ["Report
-a Vulnerability"](https://github.com/quantumlib/recirq/security/advisories/new)
-interface from the _Security_ tab of the ReCirq repository.
+before the problem can be addressed. Instead, please use the *Report a
+vulnerability* interface from the *Security* tab at the top of this GitHub
+repository page.
+
+<div align="center">
+<img width="75%" alt="Location of the report button on the repository page"
+    src="./report-vulnerability-button.png">
+</div>
 
 Please report security issues in third-party modules to the person or team
-maintaining the module rather than the  project stewards, unless you
-believe that some action needs to be taken with ReCirq in order to guard
-against the effects of a security vulnerability in a third-party module.
+maintaining the module rather than this project's stewards, unless you believe
+that some action needs to be taken specifically with this project in order to
+guard against the effects of a security vulnerability in third-party software.
 
 ## Responses to security reports
 
@@ -27,4 +33,4 @@ announcement, and may ask for additional information or guidance.
 Please contact the project stewards at Google Quantum AI via email at
 [email protected] if you have questions or other concerns. If
 for any reason you are uncomfortable reaching out to the project stewards,
-please email [email protected].
+please email [email protected] instead.