add doc

README.md

@@ -162,6 +162,10 @@ It's ok if you meet `Timeout * Async callback was not invoked within the 5000ms
 
 ## Changelog
 
+- (unreleased)
+  - Get file categories of course
+  - Get file list by category (currently not supported in TA)
+  - Fix file download url and visit count in TA
 - v3.1.4
   - Allow and check for undefined credential in login (see [#52](https://github.com/Harry-Chen/Learn-Helper/issues/52))
   - Discriminate `getAllContents` return type based on input content type (see [#53](https://github.com/Harry-Chen/Learn-Helper/issues/53))

src/index.ts

@@ -467,6 +467,7 @@ export class Learn2018Helper {
     });
   }
 
+  /** Get file categories of the specified course. */
   public async getFileCategoryList(
     courseID: string,
     courseType: CourseType = CourseType.STUDENT,
@@ -491,6 +492,10 @@ export class Learn2018Helper {
     );
   }
 
+  /**
+   * Get all files of the specified category of the specified course.
+   * Note: this cannot get `visitCount` and `downloadCount`
+   */
   public async getFileListByCategory(
     courseID: string,
     categoryId: string,