fix links

Author: bmorelli25

docs/source/index.md

@@ -6,10 +6,10 @@ Elastic Docs V3 is our next-generation documentation platform designed to improv
 
 **What do you want to do today?**
 
-* [Contribute to Elastic documentation](./contribute/index.html)
-* [Learn about migration to Elastic Docs V3](./migration/index.html)
-* [Configure content sets in V3](./configure/index.html)
-* [Learn about V3 syntax](./syntax/index.html)
+* [Contribute to Elastic documentation](./contribute/index.md)
+* [Learn about migration to Elastic Docs V3](./migration/index.md)
+* [Configure content sets in V3](./configure/index.md)
+* [Learn about V3 syntax](./syntax/index.md)
 * [Contribute to V3 (developer guide)](./development/index.md)
 
 ## About this repo

docs/source/migration/index.md

@@ -6,7 +6,7 @@ navigation_title: Migration
 We are ready to migrate our documentation to our new build system, [elastic/docs-builder](https://github.com/elastic/docs-builder)!
 
 :::{important}
-We will enforce a [Documentation Freeze](./freeze/index.html) while we migration docs between our two build systems.
+We will enforce a [Documentation Freeze](./freeze/index.md) while we migration docs between our two build systems.
 :::
 
 Migrating to Elastic Docs V3 is more than just moving to a new documentation build system. This migration also includes: