support multi language

[Delta456]

Implements #70

[Delta456]

This is not complete but I have made a draft for other people to help me figure out implement this.

To run this ./freeze --lannguage py,go main.py

main.py

def main():
   print('Hello world')
   

fmt.Println("Hello world")

EDIT: Read the below comment.

[Delta456]

I need more test cases. My implementation works.

• ./freeze --language jinja,html file.jinja

• ./freeze --language html file.jinja

• ./freeze --language jinja file.jinja

[Delta456]

As discussed in alecthomas/chroma#960 (comment), lexers.DelegatingLexer only supports syntaxes which have indeed have something in common. The implementing is working and finalised.