Update README.md

engine/README.md

 Add ${PWD}/depot_tools to PATH
 
 2. Clone the skia Repo
-
+```
+```
 
 3. Install LLVM
 
-
+
 Update out/Debug/args.gn with the following content:
 ```
 clang_win = "C:\Program Files\LLVM"
 ## How to Build Engine
 ```
 bee
-```
+```