Modify nav and add crosslinks

Author: theletterf

contribute-docs/_snippets/applies_to-key.md

@@ -33,5 +33,5 @@
   * `edot_python`: Applies to the [Elastic Distribution of OpenTelemetry Python](https://www.elastic.co/docs/reference/opentelemetry/edot-sdks/python/) (EDOT Python).
 
 :::{note}
-The `product` key and its subkeys are used to indicate feature availability and applicability. The similarly named [`products` frontmatter field](/contribute-docs/syntax/frontmatter.md#products) is used to drive elastic.co search filters.
+The `product` key and its subkeys are used to indicate feature availability and applicability. The similarly named [`products` frontmatter field](docs-builder://syntax/frontmatter.md#products) is used to drive elastic.co search filters.
 :::

contribute-docs/how-to/cumulative-docs/badge-placement.md

@@ -38,15 +38,15 @@ There are more specific guidelines on badge placement to follow when using speci
 
 ### Page frontmatter
 
-Use [`applies_to` in a page's frontmatter](/contribute-docs/syntax/applies.md#syntax) to provide signals that a page applies to the reader.
+Use [`applies_to` in a page's frontmatter](docs-builder://syntax/applies.md#syntax) to provide signals that a page applies to the reader.
 
 ::::{warning}
-Do **not** use [section-level](/contribute-docs/syntax/applies.md#section-level) or [inline annotations](/contribute-docs/syntax/applies.md#inline-level) with the page title.
+Do **not** use [section-level](docs-builder://syntax/applies.md#section-level) or [inline annotations](docs-builder://syntax/applies.md#inline-level) with the page title.
 ::::
 
 ### Headings [headings]
 
-Use [section annotations](/contribute-docs/syntax/applies.md#section-level) on the next line after a heading when the entire content between that heading and the next [heading](/contribute-docs/syntax/headings.md) of the same or higher level is version or product-specific.
+Use [section annotations](docs-builder://syntax/applies.md#section-level) on the next line after a heading when the entire content between that heading and the next [heading](docs-builder://syntax/headings.md) of the same or higher level is version or product-specific.
 
 For example, on the [Observability AI Assistant](https://www.elastic.co/docs/solutions/observability/observability-ai-assistant#choose-the-knowledge-base-language-model) page, all the content in this section is only applicable to Elastic Stack versions 9.1.0 and later.
 
@@ -58,7 +58,7 @@ For example, on the [Observability AI Assistant](https://www.elastic.co/docs/sol
 % FOR THE REVIEWER: IS THIS TRUE?
 % What do you think of allowing inline applies_to in headings as long as there is only one badge?
 :::{warning}
-Do **not** use [inline annotations](/contribute-docs/syntax/applies.md#inline-level) with headings.
+Do **not** use [inline annotations](docs-builder://syntax/applies.md#inline-level) with headings.
 
 ::::{image} ./images/heading-incorrect.png
 :screenshot:

contribute-docs/how-to/cumulative-docs/guidelines.md

@@ -50,7 +50,7 @@ For each type of applicability information, you can add `applies_to` metadata at
   or properties without disrupting the surrounding content.
 
 For a full syntax reference for page, section, and inline level `applies_to` annotations,
-refer to [](/contribute-docs/syntax/applies.md).
+refer to [Applies to](docs-builder://syntax/applies.md).
 
 ## General guidelines
 

contribute-docs/how-to/cumulative-docs/index.md

@@ -80,5 +80,5 @@ Read more about _how_ to tag content in:
   Learn how to integrate `applies_to` badges into docs content.
 * [Example scenarios](example-scenarios.md):
   Browse common scenarios you might run into as a docs contributor that require different approaches to labeling cumulative docs.
-* [`applies_to` syntax guide](/contribute-docs/syntax/applies.md):
+* [`applies_to` syntax guide](docs-builder://syntax/applies.md):
   Reference all valid values and syntax patterns available in `applies_to`.

contribute-docs/how-to/cumulative-docs/reference.md

@@ -6,7 +6,7 @@ The `applies_to` directive uses the following format:
 <key>: <lifecycle> <version>
 ```
 
-This page provides minimal reference information on the `applies_to` directive. For more detailed information, refer to [](/contribute-docs/syntax/applies.md).
+This page provides minimal reference information on the `applies_to` directive. For more detailed information, refer to [Applies to](docs-builder://syntax/applies.md).
 
 ## key