[doc] Merge Verilator note
diff --git a/sw/host/spiflash/README.md b/sw/host/spiflash/README.md
index 3901b2f..b1aea5d 100644
--- a/sw/host/spiflash/README.md
+++ b/sw/host/spiflash/README.md
@@ -28,14 +28,14 @@
 
 ## Build boot ROM and demo program
 
-If building for verilator, please add the extra option `SIM=1`
+_If building for verilator, please add the extra option `SIM=1`._
+
 Build `boot_rom`:
 ```console
 $ cd ${REPO_TOP}
 $ make -C sw SW_DIR=boot_rom clean all
 ```
 
-if building for verilator, please add the extra optoin `SIM=1`
 Build `hello_world` program:
 ```console
 $ cd ${REPO_TOP}