docs: update security url to link to central policy

.github/ISSUE_TEMPLATE/bug.md

@@ -15,7 +15,7 @@ If it is not, the issue is likely to be closed.
 Logstash Plugins are located in a different organization: [logstash-plugins](https://github.com/logstash-plugins). For bugs on specific Logstash plugins, for example, if Redis Output has a defect, please open it in the respective Redis Output repository.
 
 For security vulnerabilities please only send reports to security@elastic.co.
-See https://www.elastic.co/community/security for more information.
+See https://github.com/elastic/.github/blob/main/SECURITY.md for more information.
 
 Please fill in the following details to help us reproduce the bug:
 -->

.github/ISSUE_TEMPLATE/config.yml

@@ -4,7 +4,7 @@ contact_links:
     url: https://discuss.elastic.co/c/logstash
     about: Ask (and answer) questions here.
   - name: Security Vulnerability
-    url: https://www.elastic.co/community/security
+    url: https://github.com/elastic/.github/blob/main/SECURITY.md
     about: Send security vulnerability reports to security@elastic.co.
   - name: Plugin Issue
     url: https://github.com/logstash-plugins

CONTRIBUTING.md

@@ -44,7 +44,7 @@ Logstash user base and our own goals for the project. Through this process, we t
 ## Found a Security Issue?
 
 If you've found a security issue, before submitting anything via a PR, please
-get in touch with our security team [here](https://www.elastic.co/product-security).
+get in touch with our security team [here](https://github.com/elastic/.github/blob/main/SECURITY.md).
 
 # Contributing Documentation and Code Changes
 
@@ -163,7 +163,7 @@ Labels (optional):
 - **`[DOC]`** for a change that affects only documentation, and not code.
 - **`[SECURITY]`** for a security fix. If you're working on a security issue, 
 please make sure to follow the process outlined by our security team. 
-If you haven't done so already, please [get in touch with them](https://www.elastic.co/product-security) first.
+If you haven't done so already, please [get in touch with them](https://github.com/elastic/.github/blob/main/SECURITY.md) first.
 
 Keywords (copied from [keepachangelog.com](https://keepachangelog.com/en/1.0.0/#how)):
 
@@ -176,7 +176,7 @@ Keywords (copied from [keepachangelog.com](https://keepachangelog.com/en/1.0.0/#
   - **Important reminder**: If you're working on a security issue, please make sure
   you're following the process outlined by our security team. If you haven't
   done so already, please get in touch with them
-  [here](https://www.elastic.co/product-security) first.
+  [here](https://github.com/elastic/.github/blob/main/SECURITY.md) first.
 
 Example: