navigtion: add dxygen links and generated doxygen page link

Signed-off-by: Hofi <hofione@gmail.com>

Author: HofiOne

_data/external_links.yml

@@ -107,6 +107,12 @@ sn-ose-adminguide:
   url: https://syslog-ng.github.io/admin-guide/README
   title: [ "The syslog-ng OSE Administration Guide" ]
 
+sn-ose-source-doc:
+  id: sn-ose-source-doc
+  url: /dev-guide/chapter_9/html/index.html
+  title: [ "syslog-ng OSE source code documentation" ]
+  open_in_blank: true
+
 sn-ose-upgrade:
   id: sn-ose-upgrade
   url: https://syslog-ng.com/blog/upgrading-from-syslog-ng-open-source-to-premium-edition/
@@ -795,7 +801,12 @@ discord-wh-intro:
   id: discord-wh-intro
   url: https://support.discord.com/hc/en-us/articles/228383668-Intro-to-Webhooks
   title: [ "Discord: Intro to Webhooks" ]
-  
+
+doxygen-home:
+  id: doxygen-home
+  url: https://www.doxygen.nl/
+  title: [ "Doxygen HomePage" ]
+
 ebpf:
   id: ebpf
   url: https://ebpf.io/

_data/link_aliases.yml

@@ -104,3 +104,6 @@ adm-src-wild:
 
 adm-src-file:
   aliases: [ "/file(?:\\(\\))? source[s]?/" ]
+
+doxygen-home:
+  aliases: [ "/[Dd]oxygen/" ]

_data/navigation.yml

@@ -327,6 +327,9 @@ admin-guide-nav:
         url: /admin-guide/070_Destinations/030_Elasticsearch-http/000_Batch_mode_and_load_balancing
       - title: "elasticsearch-http() destination options"
         url: /admin-guide/070_Destinations/030_Elasticsearch-http/001_Elasticsearch-http_options
+    - title: "elasticsearch-datastream"
+      url: /admin-guide/070_Destinations/035_elasticsearch-datastream/README
+      subnav:
     - title: "file"
       url: /admin-guide/070_Destinations/040_File/README
       subnav:
@@ -1267,6 +1270,9 @@ dev-guide-nav:
       url: /dev-guide/chapter_8/section_4
     - title: "Template Function"
       url: /dev-guide/chapter_8/section_5
+  - title: "Source code documentation"
+    url: /dev-guide/chapter_9/README
+    subnav:
 
 # doc-guide
 doc-guide-nav:

doc/_dev-guide/chapter_9/README.md

@@ -0,0 +1,6 @@
+---
+title: Source code documentation
+id: dev-source-doc
+---
+
+We have the {{ site.product.short_name }} [[source code documentation|sn-ose-source-doc]] generated via Doxygen.