Fixed readme syntax highlight

README.md

@@ -4,7 +4,7 @@ Code generator to generate network packet parsers in C++ from YAML
 
 ## Installation
 
-```bash
+```
 crystal build src/andrew.cr
 sudo chown root andrew
 sudo chmod 0555 andrew
@@ -13,7 +13,7 @@ sudo mv andrew /usr/local/bin/
 
 ## Usage
 
-```bash
+```
 andrew tests/record.yml > record.cpp
 ```