Update docs

Author: vascocosta

docs/reference.md

@@ -8,6 +8,39 @@ has_children: true
 # Built-in Functions Reference
 Explore the standard library functions available in GluonScript.
 
+## Module `core`
+
+[fn append(list: List, element: Any): List](https://gluonscript.org/reference.html#fn-appendlist-list-element-any-list)
+[fn import(file: String): Record](https://gluonscript.org/reference.html#fn-importfile-string-record)
+[fn len(list: List): Int](https://gluonscript.org/reference.html#fn-lenlist-list-int)
+[fn slice(list: List, start: Int, end: Int): List](https://gluonscript.org/reference.html#fn-slicelist-list-start-int-end-int-list)
+
+## Module `conv`
+
+[]()
+
+## Module `env`
+
+[]()
+
+## Module `http`
+
+[]()
+
+## Module `io`
+
+[]()
+
+## Module `json`
+
+[]()
+
+## Module `strings`
+
+[]()
+
+---
+
 ## Module: `core`
 
 ### `fn append(list: List, element: Any): List`

docs/tutorial.md

@@ -1,6 +1,6 @@
 ---
 layout: default
-title: Reference
+title: Tutorial
 nav_order: 4
 has_children: true
 ---