[RHDHBUGS-3022]: Fix broken links found by lychee validation (#2110)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: themr0c

modules/shared/con-about-and-llama-stack.adoc

@@ -41,4 +41,4 @@ The {ls-brand-name} plugin in {product-very-short} sends prompts and receives LL
 ====
 
 .Additional resources
-* link:https://llamastack.github.io/docs#what-is-llama-stack[What is Llama Stack]
+* link:https://ogx-ai.github.io/docs/concepts[OGX (formerly Llama Stack) concepts]

modules/shared/proc-install-and-configure-a-third-party-techdocs-add-on.adoc

@@ -8,7 +8,7 @@ You can install a compatible third-party TechDocs add-on on your {product} insta
 
 .Prerequisites
 * The third-party TechDocs add-on has a valid `package.json` file in its root directory, containing all required metadata and dependencies.
-* The third-party plugin is packaged as a dynamic plugin in an OCI image. For alternative package types, see link:https://redhat-developer.github.io/red-hat-developers-documentation-rhdh/release-1.5/plugins-rhdh-install/#assembly-install-third-party-plugins-rhdh[Installing third-party plugins in {product}].
+* The third-party plugin is packaged as a dynamic plugin in an OCI image. For alternative package types, see link:{installing-and-viewing-plugins-book-link}#assembly-install-third-party-plugins-rhdh[Installing third-party plugins in {product}].
 * You have installed the `yarn` package manager.
 * The third-party plugin is packaged as a dynamic plugin in an OCI image.* You have installed and configured Node.js and NPM.