Change GitHub issue to forum link (opensearch-project#4259)

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>

Author: kolchfa-aws

_search-plugins/search-pipelines/filter-query-processor.md

@@ -9,7 +9,7 @@ grand_parent: Search
 
 # Filter query processor
 
-This is an experimental feature and is not recommended for use in a production environment. For updates on the progress of the feature or if you want to leave feedback, see the associated [GitHub issue](https://forum.opensearch.org/t/rfc-search-pipelines/12099).    
+This is an experimental feature and is not recommended for use in a production environment. For updates on the progress of the feature or if you want to leave feedback, join the discussion in the [OpenSearch forum](https://forum.opensearch.org/t/rfc-search-pipelines/12099).    
 {: .warning}
 
 The `filter_query` search request processor intercepts a search request and applies an additional query to the request, filtering the results. This is useful when you don't want to rewrite existing queries in your application but need additional filtering of the results.

_search-plugins/search-pipelines/index.md

@@ -8,7 +8,7 @@ has_toc: false
 
 # Search pipelines
 
-This is an experimental feature and is not recommended for use in a production environment. For updates on the progress of the feature or if you want to leave feedback, see the associated [GitHub issue](https://forum.opensearch.org/t/rfc-search-pipelines/12099).    
+This is an experimental feature and is not recommended for use in a production environment. For updates on the progress of the feature or if you want to leave feedback, join the discussion in the [OpenSearch forum](https://forum.opensearch.org/t/rfc-search-pipelines/12099).    
 {: .warning}
 
 You can use _search pipelines_ to build new or reuse existing result rerankers, query rewriters, and other components that operate on queries or results. Search pipelines make it easier for you to process search queries and search results within OpenSearch. Moving some of your application functionality into an OpenSearch search pipeline reduces the overall complexity of your application. As part of a search pipeline, you specify a list of processors that perform modular tasks. You can then easily add or reorder these processors to customize search results for your application. 

_search-plugins/search-pipelines/rename-field-processor.md

@@ -9,7 +9,7 @@ grand_parent: Search
 
 # Rename field processor
 
-This is an experimental feature and is not recommended for use in a production environment. For updates on the progress of the feature or if you want to leave feedback, see the associated [GitHub issue](https://forum.opensearch.org/t/rfc-search-pipelines/12099).    
+This is an experimental feature and is not recommended for use in a production environment. For updates on the progress of the feature or if you want to leave feedback, join the discussion in the [OpenSearch forum](https://forum.opensearch.org/t/rfc-search-pipelines/12099).    
 {: .warning}
 
 The `rename_field` search response processor intercepts a search response and renames the specified field. This is useful when your index and your application use different names for the same field. For example, if you rename a field in your index, the `rename_field` processor can change the new name to the old one before sending the response to your application.

_search-plugins/search-pipelines/script-processor.md

@@ -9,7 +9,7 @@ grand_parent: Search
 
 # Script processor
 
-This is an experimental feature and is not recommended for use in a production environment. For updates on the progress of the feature or if you want to leave feedback, see the associated [GitHub issue](https://forum.opensearch.org/t/rfc-search-pipelines/12099).    
+This is an experimental feature and is not recommended for use in a production environment. For updates on the progress of the feature or if you want to leave feedback, join the discussion in the [OpenSearch forum](https://forum.opensearch.org/t/rfc-search-pipelines/12099).    
 {: .warning}
 
 The `script` search request processor intercepts a search request and adds an inline Painless script that is run on incoming requests. The script can only run on the following request fields: