Merge pull request OpenXiangShan#815 from RISCVERS/fix-misleading-cmd

README.md: fix example commands

README.md

@@ -28,7 +28,7 @@ Install verilator:
 TBD
 
 Generate verilog files and compile them using verilator:
-* Move to project root, run `make emu` to compile verilator simulator. You can use `make emu config=CONFIG_NAME` to choose different size of XiangShan.
+* Move to project root, run `make emu` to compile verilator simulator. You can use `make emu CONFIG=CONFIG_NAME` to choose different size of XiangShan.
 * To speed up compiling, use `make emu REMOTE=YOUR_REMOTE_SERVER`. (If you have remote server setuped)
 
 Run program generated by verilator:
@@ -39,7 +39,7 @@ Run program generated by verilator:
 
 Example:
 ```makefile
-make emu config=MinimalSimConfig
+make emu CONFIG=MinimalSimConfig
 ./build/emu -b 0 -e 0 --force-dump-reult -i ./mem.bin
 ```