Add SearXNG to Search Engines (#4035)

Co-authored-by: Rabenherz112 <rabenherz@theravenhub.com>

README.md

@@ -1740,6 +1740,7 @@ A [search engine](https://en.wikipedia.org/wiki/Search_engine_(computing)) is an
 - [MeiliSearch](https://www.meilisearch.com) - Ultra relevant, instant and typo-tolerant full-text search API. ([Source Code](https://github.com/meilisearch/MeiliSearch)) `MIT` `Rust`
 - [OpenSearch](https://opensearch.org) - Open source distributed and RESTful search engine. ([Source Code](https://github.com/opensearch-project/OpenSearch)) `Apache-2.0` `Java`
 - [Searx](https://searx.github.io/searx/) `⚠` - Privacy-respecting, hackable metasearch engine. ([Source Code](https://github.com/searx/searx)) `AGPL-3.0` `Python`
+- [SearXNG](https://docs.searxng.org/) `⚠` - Internet metasearch engine which aggregates results from various search services and databases. (Fork of Searx). ([Source Code](https://github.com/searxng/searxng/)) `AGPL-3.0` `Python/Docker`
 - [sist2](https://github.com/simon987/sist2) - Lightning-fast file system indexer and search tool. `GPL-3.0` `C`
 - [Typesense](https://typesense.org) - Blazing fast, typo-tolerant open source search engine optimized for developer happiness and ease of use. ([Source Code](https://github.com/typesense/typesense)) `GPL-3.0` `C++`
 - [Whoogle](https://github.com/benbusby/whoogle-search) `⚠` - A self-hosted, ad-free, privacy-respecting metasearch engine. `MIT` `Python`