1.编码风格修改，宏回到全大写。

document/mem_manager/mem_manager.md

@@ -121,7 +121,7 @@ int mr_heap_init(void)
     }
 
     /* 字节向上做4对齐 */
-    size = mr_align4_up(size);
+    size = MR_ALIGN4_UP(size);
 
     /* 找到符合内存分配大小的内存块 */
     while (block->size < size)

document/mem_manager/mem_manager_EN.md

@@ -130,7 +130,7 @@ void *mr_malloc(size_t size)
     }
 
     /* Align the size to the next multiple of 4 bytes */
-    size = mr_align4_up(size);
+    size = MR_ALIGN4_UP(size);
 
     /* Find a memory block that can accommodate the requested size */
     while (block->size < size)