Add README, LICENSE, examples, fix draw parser lookahead

README: project overview, quick start, feature list, example table
LICENSE: MIT
4 new examples covering all language features:
  - arrays_and_functions: arrays, while loops, inline/regular functions
  - state_machine: multi-state flow with on enter/exit handlers
  - sprites_and_palettes: inline CHR data, palette switching, scroll, cast
  - mmc1_banked: MMC1 mapper, bank declarations, software multiply

Parser fix: draw statement keyword-arg parsing now checks for ':'
lookahead before consuming an identifier, preventing it from eating
the next statement as a keyword argument (e.g., `i += 1` after a draw).

https://claude.ai/code/session_01W6eQFStA66EuMKHUFo2rx3

examples/mmc1_banked.ne

@@ -0,0 +1,112 @@
+// MMC1 Banked — demonstrates M5 mapper and bank features.
+//
+// Shows: MMC1 mapper selection, bank declarations,
+// vertical mirroring, software multiply.
+//
+// Build: cargo run -- build examples/mmc1_banked.ne
+
+game "Banked Game" {
+    mapper: MMC1
+    mirroring: vertical
+}
+
+// Declare PRG banks for organizing code/data
+bank Level1Data: prg
+bank Level2Data: prg
+bank TileBank: chr
+
+const GRAVITY: u8 = 1
+const JUMP_VEL: u8 = 5
+const GROUND_Y: u8 = 200
+
+var px: u8 = 64
+var py: u8 = 200
+var vy: u8 = 0
+var airborne: u8 = 0
+var level: u8 = 1
+
+// Multiplication via the language (uses software multiply runtime)
+fun scale_speed(base: u8, factor: u8) -> u8 {
+    return base * factor
+}
+
+fun apply_gravity() {
+    if airborne == 1 {
+        vy += GRAVITY
+        py += vy
+        if py >= GROUND_Y {
+            py = GROUND_Y
+            airborne = 0
+            vy = 0
+        }
+    }
+}
+
+state Level1 {
+    on enter {
+        px = 64
+        py = GROUND_Y
+        level = 1
+    }
+
+    on frame {
+        // Horizontal movement with scaled speed
+        if button.right {
+            var spd: u8 = scale_speed(2, level)
+            px += spd
+        }
+        if button.left {
+            if px > 2 {
+                px -= 2
+            }
+        }
+
+        // Jump
+        if button.a {
+            if airborne == 0 {
+                airborne = 1
+                vy = JUMP_VEL
+            }
+        }
+
+        apply_gravity()
+
+        // Advance to level 2
+        if px > 230 {
+            transition Level2
+        }
+
+        draw Player at: (px, py)
+    }
+}
+
+state Level2 {
+    on enter {
+        px = 10
+        py = GROUND_Y
+        level = 2
+    }
+
+    on frame {
+        if button.right { px += 3 }
+        if button.left  { px -= 3 }
+
+        if button.a {
+            if airborne == 0 {
+                airborne = 1
+                vy = JUMP_VEL
+            }
+        }
+
+        apply_gravity()
+
+        // Loop back
+        if button.select {
+            transition Level1
+        }
+
+        draw Player at: (px, py)
+    }
+}
+
+start Level1