fix: split docs and start conceptual page (#1836)

This PR improves the guidance docs and adds a section that explains how
grammars are applied on a technical level

Author: drbh

docs/source/_toctree.yml

@@ -25,6 +25,8 @@
     title: Non-core Model Serving
   - local: basic_tutorials/safety
     title: Safety
+  - local: basic_tutorials/using_guidance
+    title: Using Guidance, JSON, tools
   - local: basic_tutorials/visual_language_models
     title: Visual Language Models
   title: Tutorials
@@ -44,6 +46,6 @@
   - local: conceptual/speculation
     title: Speculation (Medusa, ngram)
   - local: conceptual/guidance
-    title: Guidance, JSON, tools (using outlines)
+    title: How Guidance Works (via outlines)
 
   title: Conceptual Guides