Update build and install document related https://blade.ruby-lang.org/ruby-dev/39325

doc/contributing/building_ruby.md

@@ -96,11 +96,20 @@
 5. Build Ruby:
 
     ``` shell
-    make install
+    make
     ```
 
 6. [Run tests](testing_ruby.md) to confirm your build succeeded.
 
+7. Install Ruby:
+
+    ``` shell
+    make install
+    ```
+
+    - If you need to run `make install` with `sudo` and want to avoid document generation with different permissions, you can use
+    `make SUDO=sudo install`.
+
 ### Unexplainable Build Errors
 
 If you are having unexplainable build errors, after saving all your work, try running `git clean -xfd` in the source root to remove all git ignored local files. If you are working from a source directory that's been updated several times, you may have temporary build artifacts from previous releases which can cause build failures.