merged the symbol tree nodes and the unnecessary entities into the same structure
tree162e9962618a85a7a485409a24f1ecaf9a42db63
drwxr-xr-x - frith
-rw-r--r-- 0 function.cpp
drwxr-xr-x - interpreter
drwxr-xr-x - lexer
-rw-r--r-- 682 main.cpp
-rw-r--r-- 1377 symbol.cpp
drwxr-xr-x - variable