update docs/getting_started_make_guide.md

Added description of some targets, including those added with qmk#11338.

docs/getting_started_make_guide.md

@@ -14,10 +14,19 @@ The full syntax of the `make` command is `<keyboard_folder>:<keymap>:<target>`,
 The `<target>` means the following
 * If no target is given, then it's the same as `all` below
 * `all` compiles as many keyboard/revision/keymap combinations as specified. For example, `make planck/rev4:default` will generate a single .hex, while `make planck/rev4:all` will generate a hex for every keymap available to the planck.
-* `flash`, `dfu`, `teensy`, `avrdude`, `dfu-util`, or `bootloadHID` compile and upload the firmware to the keyboard. If the compilation fails, then nothing will be uploaded. The programmer to use depends on the keyboard. For most keyboards it's `dfu`, but for ChibiOS keyboards you should use `dfu-util`, and `teensy` for standard Teensys. To find out which command you should use for your keyboard, check the keyboard specific readme.
- * **Note**: some operating systems need root access for these commands to work, so in that case you need to run for example `sudo make planck/rev4:default:flash`.
+* `flash`, `dfu`, `teensy`, `avrdude`, `dfu-util`, or `bootloadHID` compile and upload the firmware to the keyboard. If the compilation fails, then nothing will be uploaded. The programmer to use depends on the keyboard. For most keyboards it's `dfu`, but for ChibiOS keyboards you should use `dfu-util`, and `teensy` for standard Teensys. To find out which command you should use for your keyboard, check the keyboard specific readme. 
+  Visit the [Flashing Firmware](flashing.md) guide for more details of the available bootloaders.
+  * **Note**: some operating systems need root access for these commands to work, so in that case you need to run for example `sudo make planck/rev4:default:flash`.
 * `clean`, cleans the build output folders to make sure that everything is built from scratch. Run this before normal compilation if you have some unexplainable problems.
 
+The following `<target>` is for developers.
+
+* `show-path` shows the path of the source and object files.
+* `dump-vars` dumps the makefile variable.
+* `objs-size` displays the size of individual object files.
+* `show_build_options` shows the options set in 'rules.mk'.
+* `check-md5` displays the md5 checksum of the generated binary file.
+
 You can also add extra options at the end of the make command line, after the target
 
 * `make COLOR=false` - turns off color output