docs: add API structure

src/app/api/README.md

@@ -0,0 +1,30 @@
+# Todoist API
+
+## Create Task
+POST /api/task
+
+## Read Task
+GET /api/task -> List all task
+GET /api/task/[taskId] -> Get specific task
+
+## Update Task
+PATCH /api/task/[taskId]
+
+## Delete Task
+DELETE /api/task/[taskId]
+
+## Task Structure
+*Subject to change*
+
+```js
+{
+    taskId: number,
+    userId: string,
+    title: string,
+    description: string,
+    dueDate: Date,
+    createdAt: Date,
+    modifiedAt: Date,
+    markedAsDone: boolean,
+}
+```