[KYUUBI #2148][DOCS] Add dev/reformat usage

### _Why are the changes needed?_

Add a `dev/reformat` usage in `developer.md`.

### _How was this patch tested?_
- [ ] Add some test cases that check the changes thoroughly including negative and positive cases if possible

- [ ] Add screenshots for manual tests if appropriate

- [x] [Run test](https://kyuubi.apache.org/docs/latest/develop_tools/testing.html#running-tests) locally before make a pull request

Closes #2149 from deadwind4/reformat-doc.

Closes #2148

0457d87 [Ada Wong] fix typo
67af7e4 [Ada Wong] [KYUUBI #2148][DOCS] Add dev/reformat usage

Authored-by: Ada Wong <rsl4@foxmail.com>
Signed-off-by: Cheng Pan <chengpan@apache.org>

Author: a49a

docs/develop_tools/developer.md

@@ -46,7 +46,15 @@ Kyuubi uses the `dev/dependencyList` file to indicate what upstream dependencies
 
 For Pull requests, a linter for dependency check will be automatically executed in GitHub Actions.
 
-
 You can run `build/dependency.sh` locally first to detect the potential dependency change first.
 
 If the changes look expected, run `build/dependency.sh --replace` to update `dev/dependencyList` in your Pull request.
+
+
+## Format All Code
+
+Kyuubi uses [Spotless](https://github.com/diffplug/spotless/tree/main/plugin-maven)
+with [google-java-format](https://github.com/google/google-java-format) and [Scalafmt](https://scalameta.org/scalafmt/)
+to format the Java and Scala code.
+
+You can run `dev/reformat` to format all Java and Scala code.