Docs rewrite

content/docs/guide/functions.mdx

@@ -0,0 +1,58 @@
+---
+title: Functions
+description: Function declarations, self parameters, return types, and unsafe functions.
+icon: Function
+---
+
+```mist
+// Return type is `void` (unit)
+void greet(str& name)
+{
+    println!("Hello, {name}");
+}
+
+// With return type
+i32 add(i32 a, i32 b)
+{
+    return a + b;
+}
+
+// Expression body (last expression is the return value)
+i32 square(i32 x)
+{
+    x * x
+}
+
+// Public function
+pub i32 multiply(i32 a, i32 b)
+{
+    a * b
+}
+
+// Generic function
+T identity<T>(T value)
+{
+    value
+}
+
+// Unsafe function
+unsafe i32 dangerous()
+{
+    42
+}
+```
+
+Function syntax: `[pub] [void | <type>] <name>[<generics>](<params>) [override] { <body> }`
+
+Functions use **Allman brace style** (opening brace on the next line).
+
+### Self Parameter
+
+Methods can take `self`, `&self`, `&mut self`, or `self` with lifetimes:
+
+```mist
+pub void set_value(&mut self, i32 v)
+{
+    self.value = v;
+}
+```