finish "parsing" of hello.jt

the AST is very ugly as it is rn. had to remove the cleanups or else its
all [[None], [None], ...]

ok im startnig to give up on doing handwritten lmao help

 - add TokenType.string
 - add read_value, read_statement, fix block reading

examples/hello.jt

@@ -5,6 +5,7 @@ import io
 
 // main can return int or void, void mains are handled by jortsc
 fn main () -> int {
-    io.puts("pants")
+    // todo: put it back to io.puts
+    ioputs("pants")
     0
 }