update readme

README.md

@@ -8,7 +8,7 @@ C++17 single-file header-only cross platform Python Interpreter.
 
 You can [try our demo on your browser](https://blueloveth.github.io/pocketpy/) or [download a prebuilt windows binary](https://github.com/blueloveTH/pocketpy/actions/workflows/main.yml).
 
-![sample_img](docs/readme_sample.png)
+![sample_img](docs/sample.png)
 
 ## Build From Source (Linux)
 
@@ -19,19 +19,14 @@ git clone https://github.com/blueloveTH/pocketpy
 cd pocketpy
 ```
 
-**If you want to get a single header file:**
+Then run
 
 ```bash
 python3 amalgamate.py
 ```
 
-It will generate `pocketpy.h` and `main.cpp` in `amalgamated/` directory. You can use `main.cpp` to build a REPL console or use `pocketpy.h` only to embed it to your game engine.
+It will generate `pocketpy.h` and `main.cpp` in `amalgamated/` directory. You can use `main.cpp` to build a REPL console or use `pocketpy.h` to embed it to your game engine.
 
-**If you want to do development:**
-
-```bash
-g++ -o pocketpy src/main.cpp --std=c++17 -O1 -pthread
-```
 ## Flutter Plugin
 
 https://github.com/blueloveTH/pocketpy-flutter