Update README with new bugtracker links

Recommendation from Chrome security folks was to use the Chromium
process for security bugs. Also crbug.com/boringssl links work now.

Also since I guess the "bug tracker" is now an "issue tracker", I
suppose we can say "issue". Meh.

Change-Id: I6c4bb81165989b3ec5f98041e4c6c2cdf52fca2f
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/70588
Auto-Submit: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>

README.md

diff --git a/README.md b/README.md
index 22ea0c7..fc5d5e2 100644
--- a/README.md
+++ b/README.md
@@ -24,12 +24,13 @@
 Project links:
 
   * [API documentation](https://commondatastorage.googleapis.com/chromium-boringssl-docs/headers.html)
-  * [Bug tracker](https://issues.chromium.org/issues?q=status:open%20componentid:1590116%2B&s=created_time:desc)
-    * [Filing new issues](https://issues.chromium.org/issues/new?component=1590116&template=2003314)
-    * [Filing new security issues](https://issues.chromium.org/issues/new?component=1590116&template=2003205)
+  * [Issue tracker](https://crbug.com/boringssl)
+    * [Filing new (public) issues](https://crbug.com/boringssl/new)
   * [CI](https://ci.chromium.org/p/boringssl/g/main/console)
   * [Code review](https://boringssl-review.googlesource.com)
 
+To file a security issue, use the [Chromium process](https://www.chromium.org/Home/chromium-security/reporting-security-bugs/) and mention in the report this is for BoringSSL. You can ignore the parts of the process that are specific to Chromium/Chrome.
+
 There are other files in this directory which might be helpful:
 
   * [PORTING.md](./PORTING.md): how to port OpenSSL-using code to BoringSSL.