describe how to report bugs in contribution guide and add missing Jump(row, col) to readme

CONTRIBUTING.md

@@ -1,3 +1,21 @@
+## Reporting an issue
+
+For reporting a bug, please make sure your report includes the following points.
+
+- How to reproduce it
+  - What text the textarea contained as pre-condition
+  - What operations you did
+  - What was the expected behavior
+  - What was the actual behavior
+- Environment
+  - Your terminal
+  - Rust version
+  - `tui` crate version
+
+An example of bug report: https://github.com/rhysd/tui-textarea/issues/1
+
+## Submitting a pull request
+
 Please ensure that all tests and linter checks passed on your branch before creating a PR which modifies some source files.
 
 To run tests:

README.md

@@ -340,6 +340,7 @@ notify how to move the cursor.
 | `textarea.move_cursor(CursorMove::Head)`             | Move cursor to the head of line           |
 | `textarea.move_cursor(CursorMove::Top)`              | Move cursor to top of lines               |
 | `textarea.move_cursor(CursorMove::Bottom)`           | Move cursor to bottom of lines            |
+| `textarea.move_cursor(CursorMove::Jump(row, col))`   | Move cursor to (row, col) position        |
 
 To define your own key mappings, simply call the above methods in your code instead of `TextArea::input()` method. The
 following example defines modal key mappings like Vim.