update README

README.md

@@ -35,7 +35,7 @@ PKG(ExampleAlg
 
 An `**algorithm**` is defined as a `c++ class` like
 
-```c++=
+```c++
 // Similar to JUNO Offline, this line will register the algorithm
 DECLARE_ALGORITHM(ExampleAlg);
 // The *Alg class must inherit from AlgBase
@@ -74,7 +74,7 @@ Similar to `ExampleAlg`, the folders, CMakeLists.txt and \_\_init\_\_.py should
 
 A `**tool**` is defined as a `c++ class` too.
 
-```c++=
+```c++
 DECLARE_TOOL(ExampleTool);
 
 class ExampleTool : public AnaTool, public ToolBase {