Small fixes to the storage_map example (#2079)

Small fix to storage_map example

Author: mohammadfawaz

examples/storage_map/src/main.sw

@@ -16,27 +16,27 @@ storage {
 abi StorageMapExample {
     #[storage(write)]fn insert_into_map1(key: u64, value: u64);
 
-    #[storage(write)]fn get_from_map1(key: u64, value: u64);
+    #[storage(read)]fn get_from_map1(key: u64, value: u64) -> u64;
 
-    #[storage(read)]fn insert_into_map2(key: (b256, bool), value: Data);
+    #[storage(write)]fn insert_into_map2(key: (b256, bool), value: Data);
 
-    #[storage(read)]fn get_from_map2(key: (b256, bool), value: Data);
+    #[storage(read)]fn get_from_map2(key: (b256, bool), value: Data) -> Data;
 }
 
 impl StorageMapExample for Contract {
     #[storage(write)]fn insert_into_map1(key: u64, value: u64) {
         storage.map1.insert(key, value);
     }
 
-    #[storage(write)]fn get_from_map1(key: u64, value: u64) {
-        storage.map1.insert(key, value);
+    #[storage(read)]fn get_from_map1(key: u64, value: u64) -> u64 {
+        storage.map1.get(key)
     }
 
-    #[storage(read)]fn insert_into_map2(key: (b256, bool), value: Data) {
-        storage.map2.get(key);
+    #[storage(write)]fn insert_into_map2(key: (b256, bool), value: Data) {
+        storage.map2.insert(key, value);
     }
 
-    #[storage(read)]fn get_from_map2(key: (b256, bool), value: Data) {
-        storage.map2.get(key);
+    #[storage(read)]fn get_from_map2(key: (b256, bool), value: Data) -> Data {
+        storage.map2.get(key)
     }
 }