fix ext links

Author: shainaraskas

docs/contribute/cumulative-docs.md

@@ -27,7 +27,7 @@ In order to achieve this, the markdown source files integrate a tagging system m
 * [Which Elastic products and deployment models the content applies to](#tagging-products-and-deployment-models) (for example, Elastic Cloud Serverless or Elastic Cloud Hosted).  
 * [When a feature goes into a new state as compared to the established base version](#tagging-version-related-changes-mandatory) (for example, being added or going from Beta to GA).
 
-This tagging system is mandatory for all of the public-facing documentation. We refer to it as “[applies_to](https://elastic.github.io/docs-builder/syntax/applies/)” tags or badges.
+This tagging system is mandatory for all of the public-facing documentation. We refer to it as “[applies_to](/syntax/applies.md)” tags or badges.
 
 ## How version awareness works in Docs V3
 
@@ -41,7 +41,7 @@ This central version config is used in certain inline version variables, and dri
 
 All documentation pages **must** include an `applies_to` tag in the YAML frontmatter. Use YAML frontmatter to indicate each deployment target's availability and lifecycle status. 
 
-The `applies_to` attribute is used to display contextual badges on each page. For the full list of supported keys and values, refer to [frontmatter](https://elastic.github.io/docs-builder/syntax/frontmatter). 
+The `applies_to` attribute is used to display contextual badges on each page. For the full list of supported keys and values, refer to [frontmatter](/syntax/frontmatter.md). 
 
 
 :::{tip}
@@ -107,7 +107,7 @@ This is true for most situations. However, it can still be useful to call it out
 
 ## Tagging version-related changes (mandatory)
 
-In the previous section, we’ve considered product and deployment availability. Feature lifecycle and version-related changes are communicated as part of the same [applies\_to](https://elastic.github.io/docs-builder/syntax/applies/) tagging logic, by specifying different values to each supported key. 
+In the previous section, we’ve considered product and deployment availability. Feature lifecycle and version-related changes are communicated as part of the same [applies_to](/syntax/applies.md) tagging logic, by specifying different values to each supported key. 
 
 **Are you sure your change is related to a specific version? Maybe not…**  
 This is a frequent case. For example: fixing typos, improving styling, adding a long-forgotten setting, etc.  

docs/migration/guide/working-in-docs-content.md

@@ -52,7 +52,7 @@ Images are in [one directory](https://github.com/elastic/docs-content/tree/main/
 * More details on the `mv` command are in [https://github.com/elastic/docs-builder/pull/376](https://github.com/elastic/docs-builder/pull/376).
 * Change the `h1` title.
 * Change the `navigation_title` in the frontmatter.
-* Add the [product availability](https://elastic.github.io/docs-builder/syntax/applies.html) to frontmatter of each page.
+* Add the [product availability](/syntax/applies.md) to frontmatter of each page.
 * Make edits to the migrated content.
 * Copy content from `raw-migrated-files` into the stub page files. Be sure to update links and image references when moving content.
   * Check if any other pages rely on the content in the `raw-migrated-files` file. You can either:

docs/syntax/quick-ref.md

@@ -590,7 +590,7 @@ Elastic Cloud Hosted supports most standard Kibana settings.
 
 ## Tabs
 
-Block element that displays content in switchable tabs to help users zero in on the right context (such as a deployment or language). [Synced tab groups](https://elastic.github.io/docs-builder/syntax/tabs/#tab-groups) are supported.
+Block element that displays content in switchable tabs to help users zero in on the right context (such as a deployment or language). [Synced tab groups](/syntax/tabs.md#tab-groups) are supported.
 
 :::::{dropdown} Syntax
 ```markdown