feat: shifted over docs guides

Author: Kapil Gowru

fern/assets/styles.css

@@ -107,7 +107,7 @@
     }
 
 
-    > a[href*="cli-api-reference"] {
+    > a[href*="cli-api"] {
       grid-column: 3;
       grid-row: 2;
 

fern/products/ask-fern/ask-fern.yml

@@ -3,19 +3,11 @@ navigation:
     contents:
       - page: What is Ask Fern?
         path: ./pages/getting-started/what-is-ask-fern.mdx
-      - page: Customer showcase
-        path: ./pages/getting-started/customer-showcase.mdx
+      - link: Customer showcase
+        href: https://buildwithfern.com/customers
   - section: Configuration
     contents:
       - page: Custom prompting
         path: ./pages/configuration/custom-prompting.mdx
-      - section: Data sources
-        contents:
-          - page: Slack
-            path: ./pages/configuration/data-sources/slack.mdx
-          - page: Discord
-            path: ./pages/configuration/data-sources/discord.mdx
-  - section: API Reference
-    contents:
-      - page: Endpoints
-        path: ./pages/api-reference/endpoints.mdx
+      - page: Citations
+        path: ./pages/configuration/citations.mdx