Update security policy with general process flow

Author: brophdawg11

SECURITY.md

@@ -18,4 +18,14 @@ To report a security issue, please use the GitHub Security Advisory [Report a Vu
 
 The React Router team will send a response indicating the next steps in handling your report. After the initial reply to your report, our team will keep you informed of the progress towards a fix and full announcement, and may ask for additional information or guidance.
 
+Generally, the full process will look something like this when we receive a new advisory via Github:
+
+- If the advisory is valid, we'll move it into `Draft` status as we begin our investigation
+- We'll inform common hosting platforms of the vulnerability so they can make any preventative changes on their end even before the vulnerability is fixed/published
+  - If you are a hosting provider and you want to be notified right away, please email us at [[email protected]](mailto:[email protected]) and we'll get you added
+- We'll publish a new version of React Router with a fix
+- We'll update our own sites with the new version
+- After a period of time, potentially up to a month or so, we'll publish the advisory
+  - This gives application developers time to update their applications to the latest version before we make the details of the advisory public
+
 Report security bugs in third-party modules to the person or team maintaining the module. You can also report a vulnerability through the [npm contact form](https://www.npmjs.com/support) by selecting "I'm reporting a security vulnerability".